https://wiki.reformrivers.eu/api.php?action=feedcontributions&user=R.c.grabowski&feedformat=atomREFORM wiki - User contributions [en]2024-03-28T12:30:51ZUser contributionsMediaWiki 1.23.5https://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2015-03-31T11:25:20Z<p>R.c.grabowski: /* Four stages of river characterization */</p>
<hr />
<div>= River Characterisation: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the river's current form and behaviour, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphological form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at each spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
= Four stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of current and past condition ==<br />
Characterisation of the spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process is extended back in time to investigate what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of key processes at each spatial scale. <br />
<br />
[[File:Indicators.png|400px|center]]<br />
<br />
The most important indicator is channel type. This reach-scale indicator summarises many of the important characteristics of the river’s hydromorphology, including river confinement, planform style and river bed sediment size. An extended river typology with 22 river types was developed, which is consistent with WFD’s high-level typology. Channel type is a core component of the final stage of the hierarchical assessment framework, in which current channel type is compared to the typologies for floodplains and groundwater:surface water interactions and the changes that have occurred over time at wider spatial scales to assess current reach condition, sensitivity and trajectories of change <br />
<br />
[[File:Typology.png|600px|center]]<br />
<br />
<br />
More details on indicators of past and present condition can be found in Chapter 8 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]].<br />
<br />
Details of the typology can be found in Chapter 7 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications [[media: Deliverable2_1_P3.pdf | (REFORM Deliverable 2.1, Part 3)]].<br />
<br />
<br />
<br />
==Stage 4: Interpreting condition, trajectories of change, and sensitivity==<br />
<br />
===Condition===<br />
The term ‘condition’ is used to capture the degree to which observed hydrogeomorphological properties conform to what would be expected in a naturally-functioning situation, and thus how far the properties have deviated from that naturally-functioning state. However, the degree to which such a deviation is seen to be small or large depends upon the biogeographical, socio-economic, and cultural context. What might be considered to be a small deviation from natural function that is of no concern in some contexts, might be seen to be a considerable and notable deviation in other contexts.<br />
<br />
Whilst the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
===Trajectories of change===<br />
The identification of “channel change”, “channel adjustment” or “trajectories of change” and their causes is fundamental to understanding the current condition and status of a reach and its response (adjustment and trajectories of change) to particular pressures.<br />
<br />
Identification of reach adjustments is based on a combination of contemporary and historical evidence and is initially investigated at the reach scale. However, such reach scale evidence more often than not reflects processes operating beyond the reach, and under such circumstances, it is crucial to consider what the processes and pressures might be that are inducing current condition and associated adjustments.<br />
<br />
Channel adjustments are most frequently induced by a distinct change in the discharge regime or the quantity of sediment supplied to the reach. Such changes may result in (i) too much sediment being supplied for river flows to move the sediment on through the reach, leading to the accumulation of sediment within the reach; or (ii) insufficient sediment being supplied to satisfy the sediment transport ability of the river flows, resulting in erosion of the bed or banks within the reach.<br />
<br />
A good tool to visualise changes is a chronology that illustrates how the channel characteristics and the factors that may have influenced them have changed over time. For example, a chronology the documents incision in a gravel bed river would record changes in bed level over time as well as the timing and magnitude of river engineering works, torrent controls, gravel mining from the channel, etc.<br />
<br />
===Sensitivity===<br />
Hydromorphological sensitivity refers to the likelihood that a particular river reach will adjust in response to imposed changes (e.g. in flow or sediment supply). In some cases negligible adjustments to imposed changes may occur, and the reach ‘accommodates’ the changes and so has negligible ‘sensitivity’ to those changes. In other cases, quite small changes in controlling processes may result in major adjustments and thus the reach is deemed ‘highly sensitive’. This is often the case when a reach is close to a threshold condition where it may change from one river type to another (see [[media: Deliverable2_1_P2.pdf | REFORM Deliverable 2.1, Part 2]], Annex G for some empirical methods for estimating proximity to threshold conditions). .<br />
<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2015-03-31T11:23:11Z<p>R.c.grabowski: /* Stage 3: Indicators */</p>
<hr />
<div>= River Characterisation: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the river's current form and behaviour, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphological form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at each spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
= Four stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of current and past condition ==<br />
Characterisation of the spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process is extended back in time to investigate what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of key processes at each spatial scale. <br />
<br />
[[File:Indicators.png|400px|center]]<br />
<br />
The most important indicator is channel type. This reach-scale indicator summarises many of the important characteristics of the river’s hydromorphology, including river confinement, planform style and river bed sediment size. An extended river typology with 22 river types was developed, which is consistent with WFD’s high-level typology. Channel type is a core component of the final stage of the hierarchical assessment framework, in which current channel type is compared to the typologies for floodplains and groundwater:surface water interactions and the changes that have occurred over time at wider spatial scales to assess current reach condition, sensitivity and trajectories of change <br />
<br />
[[File:Typology.png|600px|center]]<br />
<br />
<br />
More details on indicators of past and present condition can be found in Chapter 8 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]].<br />
<br />
Details of the typology can be found in Chapter 7 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications [[media: Deliverable2_1_P3.pdf | (REFORM Deliverable 2.1, Part 3)]].<br />
<br />
==Stage 4: Interpreting condition, trajectories of change, and sensitivity==<br />
<br />
===Condition===<br />
The term ‘condition’ is used to capture the degree to which observed hydrogeomorphological properties conform to what would be expected in a naturally-functioning situation, and thus how far the properties have deviated from that naturally-functioning state. However, the degree to which such a deviation is seen to be small or large depends upon the biogeographical, socio-economic, and cultural context. What might be considered to be a small deviation from natural function that is of no concern in some contexts, might be seen to be a considerable and notable deviation in other contexts.<br />
<br />
Whilst the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
===Trajectories of change===<br />
The identification of “channel change”, “channel adjustment” or “trajectories of change” and their causes is fundamental to understanding the current condition and status of a reach and its response (adjustment and trajectories of change) to particular pressures.<br />
<br />
Identification of reach adjustments is based on a combination of contemporary and historical evidence and is initially investigated at the reach scale. However, such reach scale evidence more often than not reflects processes operating beyond the reach, and under such circumstances, it is crucial to consider what the processes and pressures might be that are inducing current condition and associated adjustments.<br />
<br />
Channel adjustments are most frequently induced by a distinct change in the discharge regime or the quantity of sediment supplied to the reach. Such changes may result in (i) too much sediment being supplied for river flows to move the sediment on through the reach, leading to the accumulation of sediment within the reach; or (ii) insufficient sediment being supplied to satisfy the sediment transport ability of the river flows, resulting in erosion of the bed or banks within the reach.<br />
<br />
A good tool to visualise changes is a chronology that illustrates how the channel characteristics and the factors that may have influenced them have changed over time. For example, a chronology the documents incision in a gravel bed river would record changes in bed level over time as well as the timing and magnitude of river engineering works, torrent controls, gravel mining from the channel, etc.<br />
<br />
===Sensitivity===<br />
Hydromorphological sensitivity refers to the likelihood that a particular river reach will adjust in response to imposed changes (e.g. in flow or sediment supply). In some cases negligible adjustments to imposed changes may occur, and the reach ‘accommodates’ the changes and so has negligible ‘sensitivity’ to those changes. In other cases, quite small changes in controlling processes may result in major adjustments and thus the reach is deemed ‘highly sensitive’. This is often the case when a reach is close to a threshold condition where it may change from one river type to another (see [[media: Deliverable2_1_P2.pdf | REFORM Deliverable 2.1, Part 2]], Annex G for some empirical methods for estimating proximity to threshold conditions). .<br />
<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2015-03-31T11:21:02Z<p>R.c.grabowski: /* Stage 3: Indicators */</p>
<hr />
<div>= River Characterisation: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the river's current form and behaviour, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphological form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at each spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
= Four stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of current and past condition ==<br />
Characterisation of the spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process is extended back in time to investigate what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of key processes at each spatial scale. <br />
<br />
[[File:Indicators.png|400px|center]]<br />
<br />
The most important indicator is river type. This reach-scale indicator summarises many of the important characteristics of the river’s hydromorphology, including river confinement, planform style and river bed sediment size. An extended river typology with 22 river types was developed, which is consistent with WFD’s high-level typology. Reach type is a core component of the following stage of the hierarchical assessment framework, which compares the current reach type to the typologies for floodplains and groundwater:surface water interactions and the changes that have occurred over time at wider spatial scales to assess current reach condition, sensitivity and trajectories of change <br />
<br />
[[File:Typology.png|600px|center]]<br />
<br />
<br />
More details on indicators of pas and present condition can be found in Chapter 8 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]].<br />
<br />
Details of the typology can be found in Chapter 7 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications [[media: Deliverable2_1_P3.pdf | (REFORM Deliverable 2.1, Part 3)]].<br />
<br />
==Stage 4: Interpreting condition, trajectories of change, and sensitivity==<br />
<br />
===Condition===<br />
The term ‘condition’ is used to capture the degree to which observed hydrogeomorphological properties conform to what would be expected in a naturally-functioning situation, and thus how far the properties have deviated from that naturally-functioning state. However, the degree to which such a deviation is seen to be small or large depends upon the biogeographical, socio-economic, and cultural context. What might be considered to be a small deviation from natural function that is of no concern in some contexts, might be seen to be a considerable and notable deviation in other contexts.<br />
<br />
Whilst the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
===Trajectories of change===<br />
The identification of “channel change”, “channel adjustment” or “trajectories of change” and their causes is fundamental to understanding the current condition and status of a reach and its response (adjustment and trajectories of change) to particular pressures.<br />
<br />
Identification of reach adjustments is based on a combination of contemporary and historical evidence and is initially investigated at the reach scale. However, such reach scale evidence more often than not reflects processes operating beyond the reach, and under such circumstances, it is crucial to consider what the processes and pressures might be that are inducing current condition and associated adjustments.<br />
<br />
Channel adjustments are most frequently induced by a distinct change in the discharge regime or the quantity of sediment supplied to the reach. Such changes may result in (i) too much sediment being supplied for river flows to move the sediment on through the reach, leading to the accumulation of sediment within the reach; or (ii) insufficient sediment being supplied to satisfy the sediment transport ability of the river flows, resulting in erosion of the bed or banks within the reach.<br />
<br />
A good tool to visualise changes is a chronology that illustrates how the channel characteristics and the factors that may have influenced them have changed over time. For example, a chronology the documents incision in a gravel bed river would record changes in bed level over time as well as the timing and magnitude of river engineering works, torrent controls, gravel mining from the channel, etc.<br />
<br />
===Sensitivity===<br />
Hydromorphological sensitivity refers to the likelihood that a particular river reach will adjust in response to imposed changes (e.g. in flow or sediment supply). In some cases negligible adjustments to imposed changes may occur, and the reach ‘accommodates’ the changes and so has negligible ‘sensitivity’ to those changes. In other cases, quite small changes in controlling processes may result in major adjustments and thus the reach is deemed ‘highly sensitive’. This is often the case when a reach is close to a threshold condition where it may change from one river type to another (see [[media: Deliverable2_1_P2.pdf | REFORM Deliverable 2.1, Part 2]], Annex G for some empirical methods for estimating proximity to threshold conditions). .<br />
<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2015-03-31T11:09:45Z<p>R.c.grabowski: /* Four stages of river characterization */</p>
<hr />
<div>= River Characterisation: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the river's current form and behaviour, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphological form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at each spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
= Four stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of current and past condition ==<br />
Characterisation of the spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process is extended back in time to investigate what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of key processes at each spatial scale. <br />
<br />
[[File:Indicators.png|400px|center]]<br />
<br />
The most important indicator is reach type. This reach-scale indicator summarises many of the important characteristics of the river’s hydromorphology, including river confinement, planform style and river bed sediment size. An extended river typology with 22 river types was developed, which is consistent with WFD’s high-level typology. Reach type is a core component of the following stage of the hierarchical assessment framework, which compares the current reach type to the typologies for floodplains and groundwater:surface water interactions and the changes that have occurred over time at wider spatial scales to assess current reach condition, sensitivity and trajectories of change <br />
<br />
[[File:Typology.png|600px|center]]<br />
<br />
<br />
More details on indicators of pas and present condition can be found in Chapter 8 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]].<br />
<br />
Details of the typology can be found in Chapter 7 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications [[media: Deliverable2_1_P3.pdf | (REFORM Deliverable 2.1, Part 3)]].<br />
<br />
<br />
==Stage 4: Interpreting condition, trajectories of change, and sensitivity==<br />
<br />
===Condition===<br />
The term ‘condition’ is used to capture the degree to which observed hydrogeomorphological properties conform to what would be expected in a naturally-functioning situation, and thus how far the properties have deviated from that naturally-functioning state. However, the degree to which such a deviation is seen to be small or large depends upon the biogeographical, socio-economic, and cultural context. What might be considered to be a small deviation from natural function that is of no concern in some contexts, might be seen to be a considerable and notable deviation in other contexts.<br />
<br />
Whilst the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
===Trajectories of change===<br />
The identification of “channel change”, “channel adjustment” or “trajectories of change” and their causes is fundamental to understanding the current condition and status of a reach and its response (adjustment and trajectories of change) to particular pressures.<br />
<br />
Identification of reach adjustments is based on a combination of contemporary and historical evidence and is initially investigated at the reach scale. However, such reach scale evidence more often than not reflects processes operating beyond the reach, and under such circumstances, it is crucial to consider what the processes and pressures might be that are inducing current condition and associated adjustments.<br />
<br />
Channel adjustments are most frequently induced by a distinct change in the discharge regime or the quantity of sediment supplied to the reach. Such changes may result in (i) too much sediment being supplied for river flows to move the sediment on through the reach, leading to the accumulation of sediment within the reach; or (ii) insufficient sediment being supplied to satisfy the sediment transport ability of the river flows, resulting in erosion of the bed or banks within the reach.<br />
<br />
A good tool to visualise changes is a chronology that illustrates how the channel characteristics and the factors that may have influenced them have changed over time. For example, a chronology the documents incision in a gravel bed river would record changes in bed level over time as well as the timing and magnitude of river engineering works, torrent controls, gravel mining from the channel, etc.<br />
<br />
===Sensitivity===<br />
Hydromorphological sensitivity refers to the likelihood that a particular river reach will adjust in response to imposed changes (e.g. in flow or sediment supply). In some cases negligible adjustments to imposed changes may occur, and the reach ‘accommodates’ the changes and so has negligible ‘sensitivity’ to those changes. In other cases, quite small changes in controlling processes may result in major adjustments and thus the reach is deemed ‘highly sensitive’. This is often the case when a reach is close to a threshold condition where it may change from one river type to another (see [[media: Deliverable2_1_P2.pdf | REFORM Deliverable 2.1, Part 2]], Annex G for some empirical methods for estimating proximity to threshold conditions). .<br />
<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[media: Deliverable2_1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2015-03-31T10:33:10Z<p>R.c.grabowski: /* Four stages of river characterization */</p>
<hr />
<div>= River Characterisation: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the river's current form and behaviour, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphological form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at each spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
= Four stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of current and past condition ==<br />
Characterisation of the spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process is extended back in time to investigate what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[Deliverable2 1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of key processes at each spatial scale. <br />
<br />
[[File:Indicators.png|right]]<br />
<br />
The most important indicator is reach type. This reach-scale indicator summarises many of the important characteristics of the river’s hydromorphology, including river confinement, planform style and river bed sediment size. An extended river typology with 22 river types was developed, which is consistent with WFD’s high-level typology. Reach type is a core component of the following stage of the hierarchical assessment framework, which compares the current reach type to the typologies for floodplains and groundwater:surface water interactions and the changes that have occurred over time at wider spatial scales to assess current reach condition, sensitivity and trajectories of change <br />
<br />
[[File:Typology.png|center]]<br />
<br />
<br />
More details on indicators of pas and present condition can be found in Chapter 8 of the [[Deliverable2 1.pdf | REFORM Deliverable 2.1]].<br />
<br />
Details of the typology can be found in Chapter 7 of the [[Deliverable2 1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications. [[Deliverable2 1 P3.pdf | REFORM Deliverable 2.1, Part 3]].<br />
<br />
<br />
<br />
==Stage 4: Interpreting condition, trajectories of change, and sensitivity==<br />
<br />
===Condition===<br />
The term ‘condition’ is used to capture the degree to which observed hydrogeomorphological properties conform to what would be expected in a naturally-functioning situation, and thus how far the properties have deviated from that naturally-functioning state. However, the degree to which such a deviation is seen to be small or large depends upon the biogeographical, socio-economic, and cultural context. What might be considered to be a small deviation from natural function that is of no concern in some contexts, might be seen to be a considerable and notable deviation in other contexts.<br />
<br />
Whilst the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
===Trajectories of change===<br />
The identification of “channel change”, “channel adjustment” or “trajectories of change” and their causes is fundamental to understanding the current condition and status of a reach and its response (adjustment and trajectories of change) to particular pressures.<br />
<br />
Identification of reach adjustments is based on a combination of contemporary and historical evidence and is initially investigated at the reach scale. However, such reach scale evidence more often than not reflects processes operating beyond the reach, and under such circumstances, it is crucial to consider what the processes and pressures might be that are inducing current condition and associated adjustments.<br />
<br />
Channel adjustments are most frequently induced by a distinct change in the discharge regime or the quantity of sediment supplied to the reach. Such changes may result in (i) too much sediment being supplied for river flows to move the sediment on through the reach, leading to the accumulation of sediment within the reach; or (ii) insufficient sediment being supplied to satisfy the sediment transport ability of the river flows, resulting in erosion of the bed or banks within the reach.<br />
<br />
A good tool to visualise changes is a chronology that illustrates how the channel characteristics and the factors that may have influenced them have changed over time. For example, a chronology the documents incision in a gravel bed river would record changes in bed level over time as well as the timing and magnitude of river engineering works, torrent controls, gravel mining from the channel, etc.<br />
<br />
===Sensitivity===<br />
Hydromorphological sensitivity refers to the likelihood that a particular river reach will adjust in response to imposed changes (e.g. in flow or sediment supply). In some cases negligible adjustments to imposed changes may occur, and the reach ‘accommodates’ the changes and so has negligible ‘sensitivity’ to those changes. In other cases, quite small changes in controlling processes may result in major adjustments and thus the reach is deemed ‘highly sensitive’. This is often the case when a reach is close to a threshold condition where it may change from one river type to another (see Deliverable 2.1, Part 2, Annex G for some empirical methods for estimating proximity to threshold conditions). [[Deliverable2 1 P2.pdf | REFORM Deliverable 2.1, Part 2]].<br />
<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[Deliverable2 1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2015-03-31T10:27:33Z<p>R.c.grabowski: /* Four stages of river characterization */</p>
<hr />
<div>= River Characterisation: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the river's current form and behaviour, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphological form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at each spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
= Four stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of current and past condition ==<br />
Characterisation of the spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process is extended back in time to investigate what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[Deliverable2_1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of key processes at each spatial scale. <br />
<br />
[[File:Indicators.png|right]]<br />
<br />
The most important indicator is reach type. This reach-scale indicator summarises many of the important characteristics of the river’s hydromorphology, including river confinement, planform style and river bed sediment size. An extended river typology with 22 river types was developed, which is consistent with WFD’s high-level typology. Reach type is a core component of the following stage of the hierarchical assessment framework, which compares the current reach type to the typologies for floodplains and groundwater:surface water interactions and the changes that have occurred over time at wider spatial scales to assess current reach condition, sensitivity and trajectories of change <br />
<br />
[[File:Typology.png|center]]<br />
<br />
<br />
More details on indicators of pas and present condition can be found in Chapter 8 of the [[Deliverable2_1.pdf | REFORM Deliverable 2.1]].<br />
<br />
Details of the typology can be found in Chapter 7 of the [[Deliverable2_1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications. [[Deliverable2_1_P3.pdf | REFORM Deliverable 2.1, Part 3]].<br />
<br />
<br />
<br />
==Stage 4: Interpreting condition, trajectories of change, and sensitivity==<br />
<br />
===Condition===<br />
The term ‘condition’ is used to capture the degree to which observed hydrogeomorphological properties conform to what would be expected in a naturally-functioning situation, and thus how far the properties have deviated from that naturally-functioning state. However, the degree to which such a deviation is seen to be small or large depends upon the biogeographical, socio-economic, and cultural context. What might be considered to be a small deviation from natural function that is of no concern in some contexts, might be seen to be a considerable and notable deviation in other contexts.<br />
<br />
Whilst the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
===Trajectories of change===<br />
The identification of “channel change”, “channel adjustment” or “trajectories of change” and their causes is fundamental to understanding the current condition and status of a reach and its response (adjustment and trajectories of change) to particular pressures.<br />
<br />
Identification of reach adjustments is based on a combination of contemporary and historical evidence and is initially investigated at the reach scale. However, such reach scale evidence more often than not reflects processes operating beyond the reach, and under such circumstances, it is crucial to consider what the processes and pressures might be that are inducing current condition and associated adjustments.<br />
<br />
Channel adjustments are most frequently induced by a distinct change in the discharge regime or the quantity of sediment supplied to the reach. Such changes may result in (i) too much sediment being supplied for river flows to move the sediment on through the reach, leading to the accumulation of sediment within the reach; or (ii) insufficient sediment being supplied to satisfy the sediment transport ability of the river flows, resulting in erosion of the bed or banks within the reach.<br />
<br />
A good tool to visualise changes is a chronology that illustrates how the channel characteristics and the factors that may have influenced them have changed over time. For example, a chronology the documents incision in a gravel bed river would record changes in bed level over time as well as the timing and magnitude of river engineering works, torrent controls, gravel mining from the channel, etc.<br />
<br />
===Sensitivity===<br />
Hydromorphological sensitivity refers to the likelihood that a particular river reach will adjust in response to imposed changes (e.g. in flow or sediment supply). In some cases negligible adjustments to imposed changes may occur, and the reach ‘accommodates’ the changes and so has negligible ‘sensitivity’ to those changes. In other cases, quite small changes in controlling processes may result in major adjustments and thus the reach is deemed ‘highly sensitive’. This is often the case when a reach is close to a threshold condition where it may change from one river type to another (see Deliverable 2.1, Part 2, Annex G for some empirical methods for estimating proximity to threshold conditions). [[Deliverable2_1_P2.pdf | REFORM Deliverable 2.1, Part 2]].<br />
<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[Deliverable2_1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:Deliverable2_1_P3.pdfFile:Deliverable2 1 P3.pdf2015-03-31T10:26:38Z<p>R.c.grabowski: Part 3 of Deliverable 2.1</p>
<hr />
<div>Part 3 of Deliverable 2.1</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:Deliverable2_1_P2.pdfFile:Deliverable2 1 P2.pdf2015-03-31T10:25:55Z<p>R.c.grabowski: Part 2 of Deliverable 2.1</p>
<hr />
<div>Part 2 of Deliverable 2.1</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:Indicators.pngFile:Indicators.png2015-03-31T10:25:10Z<p>R.c.grabowski: Hydromorphological indicators</p>
<hr />
<div>Hydromorphological indicators</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:Typology.pngFile:Typology.png2015-03-31T10:24:37Z<p>R.c.grabowski: River reach typology</p>
<hr />
<div>River reach typology</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2015-03-31T10:23:41Z<p>R.c.grabowski: /* Four stages of river characterisation */</p>
<hr />
<div>= River Characterisation: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the river's current form and behaviour, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphological form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at each spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
= Four stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of current and past condition ==<br />
Characterisation of the spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process is extended back in time to investigate what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[Deliverable2_1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of key processes at each spatial scale. <br />
<br />
[[File:Indicators.png|right]]<br />
<br />
The most important indicator is reach type. This reach-scale indicator summarises many of the important characteristics of the river’s hydromorphology, including river confinement, planform style and river bed sediment size. An extended river typology with 22 river types was developed, which is consistent with WFD’s high-level typology. Reach type is a core component of the following stage of the hierarchical assessment framework, which compares the current reach type to the typologies for floodplains and groundwater:surface water interactions and the changes that have occurred over time at wider spatial scales to assess current reach condition, sensitivity and trajectories of change <br />
<br />
[[File:Typology.png|center]]<br />
<br />
<br />
More details on indicators of pas and present condition can be found in Chapter 8 of the [[Deliverable2_1.pdf | REFORM Deliverable 2.1]].<br />
<br />
Details of the typology can be found in Chapter 7 of the [[Deliverable2_1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications. [[Deliverable2_1_P3.pdf | REFORM Deliverable 2.1, Part 3]].<br />
<br />
==Stage 4: Interpreting condition, trajectories of change, and sensitivity==<br />
<br />
===Condition===<br />
The term ‘condition’ is used to capture the degree to which observed hydrogeomorphological properties conform to what would be expected in a naturally-functioning situation, and thus how far the properties have deviated from that naturally-functioning state. However, the degree to which such a deviation is seen to be small or large depends upon the biogeographical, socio-economic, and cultural context. What might be considered to be a small deviation from natural function that is of no concern in some contexts, might be seen to be a considerable and notable deviation in other contexts.<br />
<br />
Whilst the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
===Trajectories of change===<br />
The identification of “channel change”, “channel adjustment” or “trajectories of change” and their causes is fundamental to understanding the current condition and status of a reach and its response (adjustment and trajectories of change) to particular pressures.<br />
<br />
Identification of reach adjustments is based on a combination of contemporary and historical evidence and is initially investigated at the reach scale. However, such reach scale evidence more often than not reflects processes operating beyond the reach, and under such circumstances, it is crucial to consider what the processes and pressures might be that are inducing current condition and associated adjustments.<br />
<br />
Channel adjustments are most frequently induced by a distinct change in the discharge regime or the quantity of sediment supplied to the reach. Such changes may result in (i) too much sediment being supplied for river flows to move the sediment on through the reach, leading to the accumulation of sediment within the reach; or (ii) insufficient sediment being supplied to satisfy the sediment transport ability of the river flows, resulting in erosion of the bed or banks within the reach.<br />
<br />
A good tool to visualise changes is a chronology that illustrates how the channel characteristics and the factors that may have influenced them have changed over time. For example, a chronology the documents incision in a gravel bed river would record changes in bed level over time as well as the timing and magnitude of river engineering works, torrent controls, gravel mining from the channel, etc.<br />
<br />
===Sensitivity===<br />
Hydromorphological sensitivity refers to the likelihood that a particular river reach will adjust in response to imposed changes (e.g. in flow or sediment supply). In some cases negligible adjustments to imposed changes may occur, and the reach ‘accommodates’ the changes and so has negligible ‘sensitivity’ to those changes. In other cases, quite small changes in controlling processes may result in major adjustments and thus the reach is deemed ‘highly sensitive’. This is often the case when a reach is close to a threshold condition where it may change from one river type to another (see Deliverable 2.1, Part 2, Annex G for some empirical methods for estimating proximity to threshold conditions). [[Deliverable2_1_P2.pdf | REFORM Deliverable 2.1, Part 2]].<br />
<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[Deliverable2_1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:Deliverable2_1.pdfFile:Deliverable2 1.pdf2015-03-31T08:59:23Z<p>R.c.grabowski: Final version of Deliverable 2.1</p>
<hr />
<div>Final version of Deliverable 2.1</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2015-03-31T08:44:55Z<p>R.c.grabowski: /* River Characterization: Multi-scale Hierarchical Framework */</p>
<hr />
<div>= River Characterisation: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the river's current form and behaviour, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphological form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at each spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process can be extended back in time to provide information on what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[Deliverable2.1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a short list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of the catchment and its spatial units. Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications. <br />
<br />
Although the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
More details on indicators of pas and present condition can be found in Chapter 8 of the [[Deliverable2.1.pdf | REFORM Deliverable 2.1]].<br />
<br />
One of the reach-scale indicators is river type. An extended river typology with 22 river types is proposed that is based on river confinement, planform style, and riverbed sediment size. Details of the typology can be found in Chapter 7 of the [[Deliverable2.1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[Deliverable2.1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-23T10:00:54Z<p>R.c.grabowski: </p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
Characterisation is divided into two steps: (1) the assessment of current condition and (2) the assessment of temporal change and quantification of rates of processes <br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process can be extended back in time to provide information on what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in chapter 6 of [[Deliverable2.1.pdf | REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
The information assembled during the characterisation phases supports a short list of indicators of the current and past condition of a catchment and its spatial units. These key indicators provide an overview of current and past functioning of the catchment and its spatial units. Examples of the evaluation of indicators are provided in the volume of Annexes to this report describing Catchment Case study Applications. <br />
<br />
Although the reach scale is often the main focus of interest, indicators representative of other spatial scales, particularly of the segment and landscape units in which the reaches are situated, provide important contextual information for interpreting reach scale indicators. Multi-scale indicators can provide much management-relevant information including:<br />
# Assessing current reach condition and degree of alteration<br />
# Understanding associations between landscape unit, segment and reach properties. In other words, what types of naturally functioning reach are sustainable and feasible within particular segment and landscape unit conditions and how do degraded conditions at the reach scale reflect processes or factors operating at the segment or landscape unit scales?<br />
# Assessing potential reach condition in the context of its segment and landscape unit setting. In other words, to what extent and in what ways is the reach altered from the naturally-functioning reach types that are feasible in the segment and landscape unit setting, and to what extent does the condition of a reach conform to or differ from the condition of the segment in which it is situated?<br />
# Establishing the spatial structure and condition of the river network. In other words, analyse the distribution of reaches of different style and condition throughout the network to assess (a) the presence and spacing of reaches that are in good condition, and (b) the degree of alteration of intervening reaches. <br />
<br />
<br />
These types of information can feed into:<br />
# Identification of the best condition reaches so that they may be protected.<br />
# Selection of the most effective locations for restoration and the balance of expenditure on better condition reaches and linking reaches (according to both hydromorphological and ecological criteria).<br />
# Selection of appropriate styles of restoration for the segment and landscape unit context of reaches.<br />
<br />
More details on indicators of pas and present condition can be found in Chapter 8 of the [[Deliverable2.1.pdf | REFORM Deliverable 2.1]].<br />
<br />
One of the reach-scale indicators is river type. An extended river typology with 22 river types is proposed that is based on river confinement, planform style, and riverbed sediment size. Details of the typology can be found in Chapter 7 of the [[Deliverable2.1.pdf | REFORM Deliverable 2.1]], along with typologies for floodplains and groundwater:surface water interactions.<br />
<br />
More details on interpreting condition and trajectories of change can be found in Chapter 9 of the [[Deliverable2.1.pdf | REFORM Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-23T09:24:53Z<p>R.c.grabowski: /* Three stages of river characterization */</p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
The links below provide information on the aims of characterisation; data layers and hydromorphologically relevant parameters; potential data sources; and characteristics for each spatial unit.<br />
<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
The charactersiation process can be extended back in time to provide information on what the channel, floodplain and catchment looked like in the past; how and why they changed; and the rates of key hydromorphological processes. This provides managers with information on the underlying causes of hydromorphological degradation in a reach, the constraints on current and future management and restoration, and the likely evolutionary trajectories for the reach under different management scenarios.<br />
<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in [[Deliverable2.1.pdf | chapter 6 of REFORM Deliverable 2.1]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
(In progress)</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-23T09:04:24Z<p>R.c.grabowski: /* Characterising past condition and quantifying rates of processes */</p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in [[Deliverable2.1.pdf | chapter 6 of REFORM Deliverable 2.1]]<br />
<br />
==Stage 3: Indicators==<br />
(In progress)</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_IntroductionTemporal analysis: Introduction2014-05-23T09:03:43Z<p>R.c.grabowski: Created page with "An analysis of temporal change supports integrated catchment management and river restoration by providing the following information: * Previous condition of the catchment, fl..."</p>
<hr />
<div>An analysis of temporal change supports integrated catchment management and river restoration by providing the following information:<br />
* Previous condition of the catchment, floodplain and channel. For example, information on the channel planform in the past and whether it has changed over time.<br />
* Rates of change in channel and floodplain characteristics. For example, information on how dynamic the system is; whether the channel migrates laterally across the floodplain; and if so, how quickly it migrates, and whether this rate has changed over time.<br />
* Identification of human pressures and how they have changed over time. For example, whether land cover or use has changed; and if so, when these changes occured, and whether they have intensified, diminished or changed in spatial extent.<br />
* Channel response to past natural disturbances and human pressure. This type of information helps to appraise the current condition of the river and floodplain, the responsiveness of the river to external forcing, and where it sits in relation to thresholds for change in river patterns.<br />
* Evolutionary trajectories. By analysing the previous channel conditions, how the river has changed over time, and its links to external pressures, it is possible to have a better understanding of its past evolutionary trajectory and to start to predict likely future river channel and floodplain changes under a range of management scenarios.<br />
<br />
<br />
The purpose of [[Deliverable2.1.pdf|chapter 6]] is to summarise the techniques used to investigate change in hydromorphology over time. Recommendations are provided on the approaches to use for each characteristic, the range of data that can be collected using those approaches, suitable analytical techniques, and a general discussion of the impacts of data reliability on the interpretation of temporal change. <br />
<br />
For example applications of temporal characterisation, see the volume of Annexes to [[Deliverable2.1.pdf | REFORM Deliverable 2.1]] report describing Catchment Case study Applications. The River Frome case study, in particular, provides full details of how every stage was undertaken, including some guidance on which ArcGIS functions to use.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-23T08:56:30Z<p>R.c.grabowski: /* Characterising past condition and quantifying rates of processes */</p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
<br />
Details on recommended data sources and analytical method for charactersitics at each spatial scale are available in [[Deliverable2.1.pdf | chapter 6 of REFORM Deliverable 2.1]]<br />
<br />
==Stage 3: Indicators==<br />
(In progress)</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_IntegrationTemporal analysis: Integration2014-05-23T08:52:46Z<p>R.c.grabowski: Created page with "= Integrating data from different sources and scales= One of the main challenges of a temporal analysis is to integrate data from a wide range of sources with varying levels..."</p>
<hr />
<div>= Integrating data from different sources and scales=<br />
<br />
<br />
One of the main challenges of a temporal analysis is to integrate data from a wide range of sources with varying levels of reliability in order to detect genuine changes in the catchment, floodplain and river channel. This is where a geographical information system (GIS) becomes particularly useful. In a GIS, we are able to import graphical data based on any geographical projection of the Earth’s surface, register the data to the current projection, and assess positional accuracy. A GIS can be used to store information for a specific location, e.g. a point on a map can represent a gauging station, and its attributes can be, for example, key characteristics of the flood regime. Once the datasets are correctly loaded into a GIS, they can be queried and analysed using a veritable toolbox of techniques. <br />
<br />
<br />
A chronology (i.e. time-chart) to visualise the changes that have occurred in the catchment, riparian corridor and channel over time provides a useful way of synthesising changes and their potential causes. The chronology pulls together information on the characteristics that influence geomorphological processes and those that respond to changes in those processes. This allows changes in characteristics to be tracked over time (e.g. land cover, riparian vegetation, human interventions, channel discharge, major flood or drought events, planform pattern, channel width, etc.) and also to explore the causal linkages between them.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-23T08:51:39Z<p>R.c.grabowski: /* Characterising past condition and quantifying rates of processes */</p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
<br />
[[File:TimescalesApproaches.jpg|right]]<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]]<br />
<br />
[[Temporal analysis: Integration | Integrating data]]<br />
<br />
==Stage 3: Indicators==<br />
(In progress)</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:TimescalesApproaches.jpgFile:TimescalesApproaches.jpg2014-05-23T08:45:42Z<p>R.c.grabowski: </p>
<hr />
<div></div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_HistoricalTemporal analysis: Historical2014-05-23T08:43:02Z<p>R.c.grabowski: </p>
<hr />
<div>= Historical approaches to the temporal characterisation of hydromorphology=<br />
'''Timescale: centuries'''<br />
<br />
<br />
Historical approaches examine the human record and enable changes in hydromorphological processes and forms to be estimated or quantified. These techniques rely on documentary evidence (diaries, deeds, etc.); land and tax surveys (i.e. cadastral surveys and maps); historical maps; river topographic surveys (e.g. repeated longitudinal profiles and cross sections of river channels) and terrestrial photography. For an introduction to the use of historical data in fluvial geomorphology, see Gurnell et al. (2003) and Trimble (2012)<br />
<br />
<br />
The historical approach is applicable to all spatial scales. Due to the diversity of data sources included in this category, it is applicable to a wide range of timescales. In reality, though, the use of historical evidence is severely limited by the availability of data sources for a particularly location or time period, the type of data that is available (e.g. observations or scientific measurements), and its reliability or accuracy. <br />
<br />
<br />
Historical sources should be carefully screened before inclusion in a study of temporal change (Hooke and Kain, 1982). First an internal check of the data source should be conducted to ascertain the purpose of the source, when information was observed and subsequently published, whether it was an original survey or revision, who the observer or reporter was, what methods or instruments were used, and, for surveys and scientific data, what were the reported levels of accuracy. Second, additional sources should be used to corroborate the primary source, verifying its spatial accuracy (e.g. specific features were in the correct geographical location), attribute accuracy (e.g. features were identified correctly) and its temporal accuracy (e.g. information is correct for the reported date). As with remotely-sensed data, it is very important that accuracy be assessed so that genuine spatial and temporal changes can be differentiated from those that are artefacts of the data collection, interpretation, representation, storage or digitisation. <br />
<br />
<br />
Some historical sources, like discharge records, offer precise scientifically-derived datasets with daily or even instantaneous measurements, but most historical sources provide widely-spaced or individual snapshots of hydromorphological characteristics. For example, large-scale maps provide researchers with a variety of valuable information (e.g. channel dimensions, planform, land cover, floodplain and channel geomorphological units), but mapped features are subject to surveyor interpretation and modification for cartographic purposes, and revisions may be spaced decades apart, especially in remote or rural areas. Topographic surveys can be very valuable sources of information, but they are commonly available for only the largest streams or for streams crossing populated areas. Documentary evidence is even more limited in its utility for interpreting historical changes since it often describes only a single point in time or space, and its accuracy / precision is rarely defined. Therefore, this type of evidence must be evaluated carefully before it can be used in a robust way in hydromorphological interpretations.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_Remote_sensingTemporal analysis: Remote sensing2014-05-23T08:42:00Z<p>R.c.grabowski: </p>
<hr />
<div>= Remote sensing approaches to the temporal characterisation of hydromorphology=<br />
'''Timescale: decades'''<br />
<br />
<br />
Remote sensing approaches usually use instruments that are not in contact with the ground or water to measure their characteristics (e.g. elevation, spectral signature, etc). They may employ passive sensors that detect the electromagnetic radiation emanating from an object (e.g. photography) or active sensors that emit a signal and measure the properties of the signal after it has reflected off the object (e.g. radar). The sensors may be mounted on satellites, aircraft or at points on the Earth’s surface. Data types that are collected using remote sensing approaches include aerial photographs, multispectral, radar and laser-derived information. For an overview of remote sensing and its use in fluvial geomorphology, see Jensen (2000), Gilvear et al. (2003) and Carbonneau and Piégay (2012).<br />
<br />
<br />
Remotely-sensed data can be used at all of the spatial scales and to assess temporal changes in most hydromorphological characteristics. Its application is dependent generally on the resolution of the data and the size of the features being identified or the magnitude of change being detected. For example, high-altitude aerial photography and most freely-available satellite data (e.g. Landsat, ASTER) have high spatial coverage and low spatial resolution making them best suited for the identification and monitoring of catchment, landscape unit and segment scale characteristics. These data sources can also be used for exploring some reach characteristics on medium to large rivers (e.g. channel position and width for rivers greater than ca. 100 m in width). Conversely, low-altitude aerial surveys (e.g. photography, multi- and hyperspectral), high resolution satellite imagery (sub-metre), and laser-based techniques (airborne LiDAR and terrestrial laser scanning) have lower spatial coverage but higher spatial resolution making them better suited to segment and reach scale characterisation. Another distinction should be drawn between sources that obtain plan (2D) information (e.g. aerial photographs, multi – and hyperspectral data) that may also be interpreted to estimate heights, and those that directly produce altimetry data (e.g. LiDAR, TLS, radar).<br />
<br />
<br />
The timescale over which remote sensing can be used to investigate changes in hydromorphological characteristics is highly variable, as is the frequency of measurements that are collected. For example, airborne surveys are relatively expensive to commission, thereby limiting the frequency with which they are conducted, but these surveys often have sufficient temporal resolution to observe broad decadal to annual changes in river geomorphology. Furthermore, aerial photograph archives often date back to the mid 20th century and so predate other types of remotely sensed information. In contrast, satellite datasets offer amazing opportunities to observe changes over very short timescales: annually, seasonally or even weekly, and thus immediately before and after specific events (e.g. floods, earthquakes, etc.). For example, since the launch of NASA’s Landsat 4 satellite in 1982, Landsat Thematic Mapper data has been collecting data across the Earth’s surface every 16 days, providing multispectral information with a spatial resolution of 30 to 120 m. Landsat imagery is freely available from the USGS within 24 hours of acquisition.<br />
<br />
<br />
Remotely-sensed data products obtained from national governments or commercial sources will typically have well-defined accuracies that are detailed in accompanying manuals and technical documents. When not specified, accuracy / uncertainty can be estimated using standard techniques, such as photogrammetric and GIS-based approaches in the case of aerial photographs.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_Remote_sensingTemporal analysis: Remote sensing2014-05-23T08:41:45Z<p>R.c.grabowski: </p>
<hr />
<div>= Remote sensing approaches to the temporal characterisation of hydromorphology=<br />
'''Timescale: decades'''<br />
<br />
Remote sensing approaches usually use instruments that are not in contact with the ground or water to measure their characteristics (e.g. elevation, spectral signature, etc). They may employ passive sensors that detect the electromagnetic radiation emanating from an object (e.g. photography) or active sensors that emit a signal and measure the properties of the signal after it has reflected off the object (e.g. radar). The sensors may be mounted on satellites, aircraft or at points on the Earth’s surface. Data types that are collected using remote sensing approaches include aerial photographs, multispectral, radar and laser-derived information. For an overview of remote sensing and its use in fluvial geomorphology, see Jensen (2000), Gilvear et al. (2003) and Carbonneau and Piégay (2012).<br />
<br />
<br />
Remotely-sensed data can be used at all of the spatial scales and to assess temporal changes in most hydromorphological characteristics. Its application is dependent generally on the resolution of the data and the size of the features being identified or the magnitude of change being detected. For example, high-altitude aerial photography and most freely-available satellite data (e.g. Landsat, ASTER) have high spatial coverage and low spatial resolution making them best suited for the identification and monitoring of catchment, landscape unit and segment scale characteristics. These data sources can also be used for exploring some reach characteristics on medium to large rivers (e.g. channel position and width for rivers greater than ca. 100 m in width). Conversely, low-altitude aerial surveys (e.g. photography, multi- and hyperspectral), high resolution satellite imagery (sub-metre), and laser-based techniques (airborne LiDAR and terrestrial laser scanning) have lower spatial coverage but higher spatial resolution making them better suited to segment and reach scale characterisation. Another distinction should be drawn between sources that obtain plan (2D) information (e.g. aerial photographs, multi – and hyperspectral data) that may also be interpreted to estimate heights, and those that directly produce altimetry data (e.g. LiDAR, TLS, radar).<br />
<br />
<br />
The timescale over which remote sensing can be used to investigate changes in hydromorphological characteristics is highly variable, as is the frequency of measurements that are collected. For example, airborne surveys are relatively expensive to commission, thereby limiting the frequency with which they are conducted, but these surveys often have sufficient temporal resolution to observe broad decadal to annual changes in river geomorphology. Furthermore, aerial photograph archives often date back to the mid 20th century and so predate other types of remotely sensed information. In contrast, satellite datasets offer amazing opportunities to observe changes over very short timescales: annually, seasonally or even weekly, and thus immediately before and after specific events (e.g. floods, earthquakes, etc.). For example, since the launch of NASA’s Landsat 4 satellite in 1982, Landsat Thematic Mapper data has been collecting data across the Earth’s surface every 16 days, providing multispectral information with a spatial resolution of 30 to 120 m. Landsat imagery is freely available from the USGS within 24 hours of acquisition.<br />
<br />
<br />
Remotely-sensed data products obtained from national governments or commercial sources will typically have well-defined accuracies that are detailed in accompanying manuals and technical documents. When not specified, accuracy / uncertainty can be estimated using standard techniques, such as photogrammetric and GIS-based approaches in the case of aerial photographs.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_Field_surveyTemporal analysis: Field survey2014-05-23T08:39:33Z<p>R.c.grabowski: </p>
<hr />
<div>= Field survey approach to the temporal characterisation of hydromorphology=<br />
'''Timescale: n/a'''<br />
<br />
<br />
At the most basic level, hydromorphological change can be assessed using a geomorphological field survey. In this approach, contemporary channel and floodplain features are interpreted in the context of the channel type by a trained geomorphologist to identify changes that are ongoing or have occurred at some point in the past.<br />
<br />
<br />
The field assessment approach offers very limited temporal resolution and is applicable primarily at the reach scale. It provides an indication of channel change that has happened in the past or processes that are currently operating. For example, exposed bridge pier foundations or pipelines suggest channel bed incision ([http://eu.wiley.com/legacy/wileychi/irrigation/thorne.html Thorne, 1998]; [http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/water/manage/restoration/?cid=stelprdb1044707 NCRS 2007], Ch. 3, Table 3.2) but without any supporting information, all that can be determined is that the channel has incised at some point in time post construction. Amounts or rates of change can only be estimated if additional historical documentation exists, e.g. bridge surveys, which would then shift the analysis to the historical approach described below. On the other hand, it should be recognized that for many streams some types of data may be not available, in particular historical bed-levels, and thus geomorphological survey can be crucial to gaining information on past changes.<br />
<br />
<br />
Geomorphological field surveys can generate accurate assessments of the type and magnitude of change that has occurred in a reach over time. This is particularly true if the geomorphologist conducting the survey is familiar with the setting and river type (chapter 7), and can make comparisons with similar rivers in the area that have better historical records. Without any other supporting information, though, the uncertainty in the assessment can be high, particularly when rivers have gone through several types of changes in succession, thereby masking or removing the evidence of the earlier changes.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_PalaeoTemporal analysis: Palaeo2014-05-23T08:38:14Z<p>R.c.grabowski: Created page with "= Paleao approaches to the temporal characterisation of hydromorphology= '''Timescale: millenia''' Palaeo approaches examine the geological and archaeological record to esta..."</p>
<hr />
<div>= Paleao approaches to the temporal characterisation of hydromorphology=<br />
'''Timescale: millenia'''<br />
<br />
<br />
Palaeo approaches examine the geological and archaeological record to establish past hydromophological forms and processes. These techniques are based on sedimentology, stratigraphy and geoarchaeology, and use different techniques (e.g. C-14, OSL, geo- and dendro-chronology) for dating and estimating rates of change. For an overview of the use of palaeo data in fluvial geomorphology, see Jacobson et al. (2003).<br />
<br />
<br />
Palaeo approaches can be used at all spatial scales and to gain insight into most hydromorphological characteristics. They are the only approach capable of investigating changes in hydromorphological characteristics that have occurred over very long timescales (i.e. millennia). However, this does not imply that they are not relevant to management timescales. Traditionally their temporal resolution was quite poor, but improvements in dating techniques, particularly OSL and dendrochronology, mean that properly constrained stratigraphic layers can now be dated to a decadal or even annual resolution. Consequently, sedimentology and stratigraphy can be used to investigate significant changes in hydromorphological characteristics that occurred thousands of years ago, but they can also be used to document recent changes. Stratigraphic and sedimentological evidence is commonly paired with geomorphological surveys (Section 6.1.1) to shed light on the underlying mechanisms and rates of change.<br />
<br />
<br />
The accuracy of palaeo approaches is dependent on the techniques used, the skill and experience of the scientist to identify forms and interpret processes, and the level to which sediment strata can be constrained and dated. Specialist texts should be referred to for estimates of accuracy if palaeo approaches are used.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_HistoricalTemporal analysis: Historical2014-05-23T08:36:08Z<p>R.c.grabowski: </p>
<hr />
<div>Historical approaches examine the human record and enable changes in hydromorphological processes and forms to be estimated or quantified. These techniques rely on documentary evidence (diaries, deeds, etc.); land and tax surveys (i.e. cadastral surveys and maps); historical maps; river topographic surveys (e.g. repeated longitudinal profiles and cross sections of river channels) and terrestrial photography. For an introduction to the use of historical data in fluvial geomorphology, see Gurnell et al. (2003) and Trimble (2012)<br />
<br />
<br />
The historical approach is applicable to all spatial scales. Due to the diversity of data sources included in this category, it is applicable to a wide range of timescales. In reality, though, the use of historical evidence is severely limited by the availability of data sources for a particularly location or time period, the type of data that is available (e.g. observations or scientific measurements), and its reliability or accuracy. <br />
<br />
<br />
Historical sources should be carefully screened before inclusion in a study of temporal change (Hooke and Kain, 1982). First an internal check of the data source should be conducted to ascertain the purpose of the source, when information was observed and subsequently published, whether it was an original survey or revision, who the observer or reporter was, what methods or instruments were used, and, for surveys and scientific data, what were the reported levels of accuracy. Second, additional sources should be used to corroborate the primary source, verifying its spatial accuracy (e.g. specific features were in the correct geographical location), attribute accuracy (e.g. features were identified correctly) and its temporal accuracy (e.g. information is correct for the reported date). As with remotely-sensed data, it is very important that accuracy be assessed so that genuine spatial and temporal changes can be differentiated from those that are artefacts of the data collection, interpretation, representation, storage or digitisation. <br />
<br />
<br />
Some historical sources, like discharge records, offer precise scientifically-derived datasets with daily or even instantaneous measurements, but most historical sources provide widely-spaced or individual snapshots of hydromorphological characteristics. For example, large-scale maps provide researchers with a variety of valuable information (e.g. channel dimensions, planform, land cover, floodplain and channel geomorphological units), but mapped features are subject to surveyor interpretation and modification for cartographic purposes, and revisions may be spaced decades apart, especially in remote or rural areas. Topographic surveys can be very valuable sources of information, but they are commonly available for only the largest streams or for streams crossing populated areas. Documentary evidence is even more limited in its utility for interpreting historical changes since it often describes only a single point in time or space, and its accuracy / precision is rarely defined. Therefore, this type of evidence must be evaluated carefully before it can be used in a robust way in hydromorphological interpretations.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_HistoricalTemporal analysis: Historical2014-05-23T08:35:40Z<p>R.c.grabowski: Created page with "Historical approaches examine the human record and enable changes in hydromorphological processes and forms to be estimated or quantified. These techniques rely on documentary..."</p>
<hr />
<div>Historical approaches examine the human record and enable changes in hydromorphological processes and forms to be estimated or quantified. These techniques rely on documentary evidence (diaries, deeds, etc.); land and tax surveys (i.e. cadastral surveys and maps); historical maps; river topographic surveys (e.g. repeated longitudinal profiles and cross sections of river channels) and terrestrial photography. For an introduction to the use of historical data in fluvial geomorphology, see Gurnell et al. (2003) and Trimble (2012)<br />
<br />
The historical approach is applicable to all spatial scales. Due to the diversity of data sources included in this category, it is applicable to a wide range of timescales. In reality, though, the use of historical evidence is severely limited by the availability of data sources for a particularly location or time period, the type of data that is available (e.g. observations or scientific measurements), and its reliability or accuracy. <br />
<br />
Historical sources should be carefully screened before inclusion in a study of temporal change (Hooke and Kain, 1982). First an internal check of the data source should be conducted to ascertain the purpose of the source, when information was observed and subsequently published, whether it was an original survey or revision, who the observer or reporter was, what methods or instruments were used, and, for surveys and scientific data, what were the reported levels of accuracy. Second, additional sources should be used to corroborate the primary source, verifying its spatial accuracy (e.g. specific features were in the correct geographical location), attribute accuracy (e.g. features were identified correctly) and its temporal accuracy (e.g. information is correct for the reported date). As with remotely-sensed data, it is very important that accuracy be assessed so that genuine spatial and temporal changes can be differentiated from those that are artefacts of the data collection, interpretation, representation, storage or digitisation. <br />
<br />
Some historical sources, like discharge records, offer precise scientifically-derived datasets with daily or even instantaneous measurements, but most historical sources provide widely-spaced or individual snapshots of hydromorphological characteristics. For example, large-scale maps provide researchers with a variety of valuable information (e.g. channel dimensions, planform, land cover, floodplain and channel geomorphological units), but mapped features are subject to surveyor interpretation and modification for cartographic purposes, and revisions may be spaced decades apart, especially in remote or rural areas. Topographic surveys can be very valuable sources of information, but they are commonly available for only the largest streams or for streams crossing populated areas. Documentary evidence is even more limited in its utility for interpreting historical changes since it often describes only a single point in time or space, and its accuracy / precision is rarely defined. Therefore, this type of evidence must be evaluated carefully before it can be used in a robust way in hydromorphological interpretations.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_Remote_sensingTemporal analysis: Remote sensing2014-05-23T08:32:46Z<p>R.c.grabowski: Created page with "Remote sensing approaches usually use instruments that are not in contact with the ground or water to measure their characteristics (e.g. elevation, spectral signature, etc). ..."</p>
<hr />
<div>Remote sensing approaches usually use instruments that are not in contact with the ground or water to measure their characteristics (e.g. elevation, spectral signature, etc). They may employ passive sensors that detect the electromagnetic radiation emanating from an object (e.g. photography) or active sensors that emit a signal and measure the properties of the signal after it has reflected off the object (e.g. radar). The sensors may be mounted on satellites, aircraft or at points on the Earth’s surface. Data types that are collected using remote sensing approaches include aerial photographs, multispectral, radar and laser-derived information. For an overview of remote sensing and its use in fluvial geomorphology, see Jensen (2000), Gilvear et al. (2003) and Carbonneau and Piégay (2012).<br />
<br />
<br />
Remotely-sensed data can be used at all of the spatial scales and to assess temporal changes in most hydromorphological characteristics. Its application is dependent generally on the resolution of the data and the size of the features being identified or the magnitude of change being detected. For example, high-altitude aerial photography and most freely-available satellite data (e.g. Landsat, ASTER) have high spatial coverage and low spatial resolution making them best suited for the identification and monitoring of catchment, landscape unit and segment scale characteristics. These data sources can also be used for exploring some reach characteristics on medium to large rivers (e.g. channel position and width for rivers greater than ca. 100 m in width). Conversely, low-altitude aerial surveys (e.g. photography, multi- and hyperspectral), high resolution satellite imagery (sub-metre), and laser-based techniques (airborne LiDAR and terrestrial laser scanning) have lower spatial coverage but higher spatial resolution making them better suited to segment and reach scale characterisation. Another distinction should be drawn between sources that obtain plan (2D) information (e.g. aerial photographs, multi – and hyperspectral data) that may also be interpreted to estimate heights, and those that directly produce altimetry data (e.g. LiDAR, TLS, radar).<br />
<br />
<br />
The timescale over which remote sensing can be used to investigate changes in hydromorphological characteristics is highly variable, as is the frequency of measurements that are collected. For example, airborne surveys are relatively expensive to commission, thereby limiting the frequency with which they are conducted, but these surveys often have sufficient temporal resolution to observe broad decadal to annual changes in river geomorphology. Furthermore, aerial photograph archives often date back to the mid 20th century and so predate other types of remotely sensed information. In contrast, satellite datasets offer amazing opportunities to observe changes over very short timescales: annually, seasonally or even weekly, and thus immediately before and after specific events (e.g. floods, earthquakes, etc.). For example, since the launch of NASA’s Landsat 4 satellite in 1982, Landsat Thematic Mapper data has been collecting data across the Earth’s surface every 16 days, providing multispectral information with a spatial resolution of 30 to 120 m. Landsat imagery is freely available from the USGS within 24 hours of acquisition.<br />
<br />
<br />
Remotely-sensed data products obtained from national governments or commercial sources will typically have well-defined accuracies that are detailed in accompanying manuals and technical documents. When not specified, accuracy / uncertainty can be estimated using standard techniques, such as photogrammetric and GIS-based approaches in the case of aerial photographs.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Temporal_analysis:_Field_surveyTemporal analysis: Field survey2014-05-23T08:27:40Z<p>R.c.grabowski: Created page with "At the most basic level, hydromorphological change can be assessed using a geomorphological field survey. In this approach, contemporary channel and floodplain features are in..."</p>
<hr />
<div>At the most basic level, hydromorphological change can be assessed using a geomorphological field survey. In this approach, contemporary channel and floodplain features are interpreted in the context of the channel type by a trained geomorphologist to identify changes that are ongoing or have occurred at some point in the past.<br />
<br />
The field assessment approach offers very limited temporal resolution and is applicable primarily at the reach scale. It provides an indication of channel change that has happened in the past or processes that are currently operating. For example, exposed bridge pier foundations or pipelines suggest channel bed incision ([http://eu.wiley.com/legacy/wileychi/irrigation/thorne.html Thorne, 1998]; [http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/water/manage/restoration/?cid=stelprdb1044707 NCRS 2007], Ch. 3, Table 3.2) but without any supporting information, all that can be determined is that the channel has incised at some point in time post construction. Amounts or rates of change can only be estimated if additional historical documentation exists, e.g. bridge surveys, which would then shift the analysis to the historical approach described below. On the other hand, it should be recognized that for many streams some types of data may be not available, in particular historical bed-levels, and thus geomorphological survey can be crucial to gaining information on past changes.<br />
<br />
Geomorphological field surveys can generate accurate assessments of the type and magnitude of change that has occurred in a reach over time. This is particularly true if the geomorphologist conducting the survey is familiar with the setting and river type (chapter 7), and can make comparisons with similar rivers in the area that have better historical records. Without any other supporting information, though, the uncertainty in the assessment can be high, particularly when rivers have gone through several types of changes in succession, thereby masking or removing the evidence of the earlier changes.</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-23T08:03:25Z<p>R.c.grabowski: </p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in the preceding links. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]] <br />
<br />
<br />
[[File:TimescalesApproaches.jpg]]<br />
<br />
<br />
<br />
==Stage 3: Indicators==<br />
(In progress)</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-23T07:57:42Z<p>R.c.grabowski: </p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Geomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in Table 4.1. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]] <br />
<br />
<br />
[[File:TimescalesApproaches.jpg]]<br />
<br />
<br />
<br />
==Stage 3: Indicators==<br />
(In progress)</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-22T14:59:18Z<p>R.c.grabowski: </p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
=== Delineating the spatial units ===<br />
[[Media:Table 4.1Delineation.pdf | Table 4.1]] lists the hierarchy of spatial scales within the REFORM framework, provides a definition of each scale, the criteria that are used to delineate the spatial units, and some possible data sources to support delineation. <br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in Table 4.1. <br />
<br />
<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Heomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys, and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]] <br />
<br />
<br />
[[File:TimescalesApproaches.jpg]]<br />
<br />
<br />
<br />
==Stage 3: Indicators==<br />
(In progress)</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-22T14:57:43Z<p>R.c.grabowski: </p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
<br />
<br />
=== Delineating the spatial units ===<br />
[[Media:Table 4.1Delineation.pdf | Table 4.1]] lists the hierarchy of spatial scales within the REFORM framework, provides a definition of each scale, the criteria that are used to delineate the spatial units, and some possible data sources to support delineation. <br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in Table 4.1. <br />
<br />
<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Heomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys, and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
<br />
[[Temporal analysis: Introduction | Introduction]]<br />
<br />
[[Temporal analysis: Field survey | Field survey]]<br />
<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
<br />
[[Temporal analysis: Historical | Historical information]]<br />
<br />
[[Temporal analysis: Palaeo | Palaeo techniques]] <br />
<br />
<br />
[[File:TimescalesApproaches.jpg]]<br />
<br />
<br />
==Stage 3: Indicators==<br />
(In progress)</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Unit_characterisationUnit characterisation2014-05-22T14:56:24Z<p>R.c.grabowski: Created page with "=Geomorphic unit= == Aim == Identification of the type and abundance of geomorphic units present and interpret their significance in relation to reach-scale morphodynamics =..."</p>
<hr />
<div>=Geomorphic unit=<br />
== Aim ==<br />
Identification of the type and abundance of geomorphic units present and interpret their significance in relation to reach-scale morphodynamics<br />
<br />
<br />
== Data layers and hydromorphologically relevant parameters==<br />
Remotely-sensed data sets (including Google Earth) can provide initial assessments. Lidar is excellent for identifying units beneath vegetation<br />
<br />
Habitat, morphology and riparian surveys provide additional but widely varying information according to the conventions used in different EU member states.<br />
<br />
<br />
== Potential data sources ==<br />
* Google Earth<br />
* Orthophotos<br />
* Multi-spectral remotely-sensed data<br />
* Lidar data<br />
* National surveys including: Physical habitat surveys, Riparian habitat surveys, Morphological surveys<br />
(Field reconnaissance can provide useful confirmation / additional data)<br />
<br />
<br />
==Characteristics==<br />
===Information from aerial imagery===<br />
Identification of channel and floodplain geomorphic features from aerial imagery <br />
<br />
===Information from field survey===<br />
Information drawn from existing or purpose specific field surveys<br />
to: (1) confirm and extend features identified from aerial imagery; (2) identify characteristics that suggest particular trajectories of channel changes<br />
<br />
<br />
More details on the characterisation of geomorphic units can be found in [[media:Deliverable2.1.pdf|chapter 5 of Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-22T14:51:32Z<p>R.c.grabowski: </p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
<br />
<br />
=== Delineating the spatial units ===<br />
[[Media:Table 4.1Delineation.pdf | Table 4.1]] lists the hierarchy of spatial scales within the REFORM framework, provides a definition of each scale, the criteria that are used to delineate the spatial units, and some possible data sources to support delineation. <br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in Table 4.1. <br />
<br />
<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
''Units: '' Heomorphic untis, hydraulic uinits and river elements do not require ‘delineation’ at this stage of the analysis, but in later analytical stages we emphasise the identification of geomorphic units as key characteristics of river reaches. <br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys, and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
[[Unit characterisation|Unit]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
[[Temporal analysis: Introduction | Introduction]]<br />
[[Temporal analysis: Field survey | Field survey]]<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
[[Temporal analysis: Historical | Historical information]]<br />
[[Temporal analysis: Palaeo | Palaeo techniques]] <br />
<br />
[[File:TimescalesApproaches.jpg]]</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Reach_characterisationReach characterisation2014-05-22T14:48:14Z<p>R.c.grabowski: Created page with "= Reach = == Aim == Characterisation of river energy, channel and floodplain dimensions, morphology /geomorphic units, sediments, vegetation and physical pressures, including:..."</p>
<hr />
<div>= Reach =<br />
== Aim ==<br />
Characterisation of river energy, channel and floodplain dimensions, morphology /geomorphic units, sediments, vegetation and physical pressures, including:<br />
* Quantification of channel dimensions<br />
* Stream power<br />
* Bed and bank sediment calibre<br />
* Vegetation extent and structure / patchiness<br />
* Pressures, particularly on lateral connectivity.<br />
<br />
<br />
== Data layers and hydromorphologically relevant parameters==<br />
Remotely-sensed data sets (including Google Earth) can provide much of the basic information on channel dimensions, hydromorphological and vegetation features (geomorphic units) and sometimes a crude indication of bed material size. Flow information is drawn from the segment scale.<br />
<br />
DEMs provide reach slope estimates. <br />
<br />
Where available, Lidar surveys provide very accurate information on channel slope, channel-floodplain morphology and width, and riparian vegetation distribution, height and structure.<br />
<br />
<br />
== Potential data sources ==<br />
* Google Earth<br />
* Orthophotos<br />
* Multi-spectral remotely-sensed data<br />
* Digital Elevation Models (e.g. [http://epp.eurostat.ec.europa.eu/portal/page/portal/gisco_Geographical_information_maps/geodata/digital_elevation_model EU-GDEM])<br />
* Lidar data <br />
* Pan-European and National vegetation databases<br />
<br />
<br />
== Characteristics ==<br />
===Channel dimensions===<br />
''Channel dimensions: '' (1) Average reach and channel gradients; (2) Bankfull and baseflow channel width; (3) Bankful and baseflow channel sinuosity index (4) Braiding index (5) Anabranching index<br />
<br />
===River energy===<br />
''River energy: '' (1) total stream power; (2) specific stream power; (3) average bed shear stress<br />
<br />
===Bank and bed sediment===<br />
''Sediment size: '' (1) Bedrock exposure; (2) Composition (>64 mm); (3) Composition (<64 mm)<br />
<br />
===Riparian and aquatic vegetation===<br />
''Riparian vegetation: '' (1) Age structure; (2) Lateral structure; (3) Patchiness; (4) Species<br />
<br />
''Large wood: '' (1) Large wood presence and abundance<br />
<br />
''Aquatic vegetation: '' (1) Extent; (2) Patchiness; (3) Species presence and abundance<br />
<br />
===Physical pressures and impacts===<br />
''River bed condition: '' (1) Bed armouring (gravel-bed rivers); (2) Bed clogging / burial (gravel-bed rivers); (3) extent of bed reinforcement; (4) number of channel blocking structures; (5) sediment, wood, vegetation removal<br />
<br />
''River bank condition and lateral continuity: '' (1) hard bank reinforcement; (2) bank edge levées/embankments; (3) set-back levées/embankments; (4) bank top infrastructure; (5) immobilised river margin; (6) actively eroding river margin; (7) width of erodible corridor; (8) number of channel-crossing /blocking structures<br />
<br />
''Riparian corridor connectivity and condition: '' (1) floodplain accessible by flood water; (2) riparian corridor accessible by flood water; (3) riparian corridor affected by intense woodland management activities; (4) abundance of alien, invasive plant species; (5) extent of impervious cover, severe soil compaction, excavations / extractions / infilling<br />
<br />
<br />
More details on the characterisation of reaches can be found in [[media:Deliverable2.1.pdf|chapter 5 of Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Segment_characterisationSegment characterisation2014-05-22T14:35:09Z<p>R.c.grabowski: Created page with "= Segment = == Aim == Characterisation of the process domains associated with fluvial processes at the segment scale and the physical pressures affecting them: Characteristic..."</p>
<hr />
<div>= Segment =<br />
== Aim ==<br />
Characterisation of the process domains associated with fluvial processes at the segment scale and the physical pressures affecting them:<br />
<br />
Characteristics and their quantification: <br />
* Flow regime<br />
* Valley characteristics<br />
* Sediment size and delivery<br />
* Riparian corridor features<br />
* Physical pressures<br />
<br />
<br />
== Data layers and hydromorphologically relevant parameters==<br />
* River flow records assembled or modelled and ‘natural’ flow record assembled / estimated.<br />
* DEMs analysed to estimate average valley slope and, for larger rivers, indication of river confinement within its valley. <br />
* Analysis of aerial imagery, (where available) Lidar, and (for river bed sediment) existing morphological/habitat surveys to assess characteristics of the valley, riparian corridor and longitudinal physical pressures.<br />
<br />
<br />
== Potential data sources ==<br />
* Flow gauging station records<br />
* Digital elevation models [e.g. [http://epp.eurostat.ec.europa.eu/portal/page/portal/gisco_Geographical_information_maps/geodata/digital_elevation_model EU-GDEM])<br />
* Google Earth images<br />
* Multi-spectral remotely-sensed data <br />
* Orthophotos<br />
* Lidar data<br />
* National surveys including: Physical habitat surveys, Riparian habitat surveys, Morphological surveys<br />
<br />
<br />
== Characteristics ==<br />
==== Flow regime====<br />
''Flow regime classification:'' (1) Assign to one of nine regime types; (2) Annual pattern of monthly flows<br />
<br />
''Flow characteristics:'' (1) Morphologically representative flows: median, 2yr or 10 yr frequency flood flows (Qpmedian; Qp2; Qp10.); (2) Extreme flows; (3) Abrupt anthropogenic flow: number, size, duration.<br />
<br />
===Valley characteristics===<br />
''Valley characteristics:'' (1) gradient; (2) degree of valley confinement; (3) degree of river confinement.<br />
<br />
===Sediment===<br />
''Sediment size:'' (1) dominant bed material calibre<br />
<br />
''Lateral sediment delivery:'' (1) eroded soil delivered to channel; (2) land surface instabilities connected to channel; (3) sediment delivery from bank erosion<br />
<br />
''Sediment load and budget:'' (1) estimated sediment transport; (2) segment gaining, losing or in-balance with respect to sediment transfer.<br />
<br />
===Riparian vegetation===<br />
''Presence of a riparian corridor:'' (1) average width; (2) area; (3) proportion of valley bottom; (4) continuity<br />
<br />
''Riparian corridor vegetation coverage:'' (1) proportion trees, shrubs, short herbaceous, bare ground<br />
<br />
''Wood delivery potential:'' (1) proportion bank top under mature trees<br />
<br />
===Physical pressures===<br />
''Longitudinal continuity:'' (1) channel blocking structures; (2) channel crossing / partial blocking structures<br />
<br />
<br />
More details on the characterisation of segments can be found in [[media:Deliverable2.1.pdf|chapter 5 of Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Landscape_unit_characterisationLandscape unit characterisation2014-05-22T14:21:22Z<p>R.c.grabowski: Created page with "= Landscape unit = == Aim == Characterisation of the form and process domain(s) associated with water and sediment delivery potential of the landscape unit: * Rainfall * Topo..."</p>
<hr />
<div>= Landscape unit =<br />
<br />
== Aim ==<br />
Characterisation of the form and process domain(s) associated with water and sediment delivery potential of the landscape unit:<br />
* Rainfall<br />
* Topography (broad characterisation of elevation range, slope, form)<br />
* Geology / soils (aquifers and weathering/erosion susceptibility) <br />
* Land cover, which controls water and sediment delivery to the drainage network<br />
* Natural riparian vegetation influences interaction between hillslopes/floodplain and river network. <br />
* Physical pressures / human influences on sediment regime by hydropower plants or retention structures (only needed if all upstream segments or reaches are not being characterised<br />
<br />
<br />
== Data layers and hydromorphologically relevant parameters== <br />
''Essential GIS layers:'' DEM, geology (solid), land cover. <br />
<br />
''Optional GIS layers:'' soil permeability; geology (superficial); rainfall records<br />
<br />
<br />
From these and aerial imagery derive measures of landscape form, river network extent, erosion susceptibility. <br />
<br />
Assemble appropriate publications, maps and databases to establish potential ‘natural’ floodplain forests or riparian (and aquatic) vegetation.<br />
<br />
Data sets are required which indicate the position of hydropower plants, retention structures and their ability to totally or partially retaining sediments and large wood.<br />
<br />
<br />
== Potential data sources ==<br />
* Digital Elevation Models [e.g. [http://epp.eurostat.ec.europa.eu/portal/page/portal/gisco_Geographical_information_maps/geodata/digital_elevation_model EU-GDEM]) <br />
* [http://ccm.jrc.ec.europa.eu/php/index.php?action=view&id=23 CCM2 River and Catchment Database (v2.1)]<br />
* [http://www.eea.europa.eu/data-and-maps/data/european-catchments-and-rivers-network Ecrins database]<br />
* [http://onegeology-europe.org/ One Geology Europe]<br />
* [http://eusoils.jrc.ec.europa.eu/library/esdac/OnLine_Data.cfm European soils data base](soils maps, USLE K erodibility factor, Pesera soil erosion estamates, landslide susceptibility)<br />
* [http://www.eea.europa.eu/data-and-maps CORINE land cover]<br />
* [http://forest.jrc.ec.europa.eu/download/data/ JRC Forest Cover Map]<br />
* Google Earth / other satellite imagery / Orthophotos<br />
<br />
<br />
== Characteristics ==<br />
=== Water delivery potential ===<br />
''Rainfall: '' (1) summary characteristics of rainfall amount and regime <br />
<br />
''Relief / Topoography: '' (1) drainage density; (2) hypsometric curve; (3) surface slope - elevation<br />
<br />
''Surface:Groundwater: '' proportion of landscape unit with (1) exposed aquifers; (2) soil/rock permeability classes<br />
<br />
''Land cover: '' (1) proportion of landscape unit under land cover classes (Corine – Level 2)<br />
<br />
=== Sediment production===<br />
''Potential fine sediment production: '' (1) soil erosion map layer; (2) average soil erosion rate<br />
<br />
''Potential coarse sediment production: '' (1) potential sources map layer; (2) Sources-slope gradient map layer<br />
<br />
=== Physical pressures on sediment regime ===<br />
''Total or partial retention of sediment and large wood by hydropower plants: '' (1) Hydropower plant layer (location, type, size etc); (2) Other retention structures map layer (location, type, size etc).<br />
<br />
''Total or partial retention of sediment and large wood by other structures (e.g. torrent control structures)''<br />
<br />
(Physical pressures only required if a full characterisation of all segments is not intended)<br />
<br />
<br />
More details on the characterisation of landscape units can be found in [[media:Deliverable2.1.pdf|chapter 5 of Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Catchment_characterisationCatchment characterisation2014-05-22T13:42:56Z<p>R.c.grabowski: </p>
<hr />
<div>= Catchment characterisation =<br />
<br />
== Aim ==<br />
Characterisation of the size, morphology, geological/soil and land cover controls on water (including groundwater) and sediment delivery to the drainage network.<br />
<br />
<br />
== Data layers and hydromorphologically relevant parameters==<br />
''Essential GIS layers:'' DEM, geology (solid), land cover<br />
<br />
''Optional GIS layers:'' soil permeability; geology (superficial). <br />
<br />
<br />
From these derive the catchment area, relief, extent of broad land cover types and extent of broad rock types. The latter can be subdivided according to their water holding properties (aquifers, aquicludes, aquifuges) and susceptibility to weathering / erosion.<br />
<br />
<br />
== Potential data sources ==<br />
* Digital Elevation Models [e.g. [http://epp.eurostat.ec.europa.eu/portal/page/portal/gisco_Geographical_information_maps/geodata/digital_elevation_model EU-GDEM]) <br />
* [http://ccm.jrc.ec.europa.eu/php/index.php?action=view&id=23 CCM2 River and Catchment Database (v2.1)]<br />
* [http://www.eea.europa.eu/data-and-maps/data/european-catchments-and-rivers-network Ecrins database]<br />
* [http://onegeology-europe.org/ One Geology Europe]<br />
* [http://eusoils.jrc.ec.europa.eu/library/esdac/OnLine_Data.cfm European soils data base]<br />
* [http://www.eea.europa.eu/data-and-maps CORINE land cover]<br />
* [http://forest.jrc.ec.europa.eu/download/data/ JRC Forest Cover Map]<br />
<br />
<br />
== Characteristics ==<br />
===Size, morphology and hydrological balance ===<br />
* Catchment area<br />
* WFD size category<br />
* Maximum, average and minimum elevation<br />
* Relative relief<br />
* WFD elevation zones<br />
* Average rainfall and runoff<br />
<br />
===Geology and soils ===<br />
Proportion of catchment with:<br />
* Exposed aquifers<br />
* Rock type classes<br />
* Soil permeability classes<br />
<br />
===Land cover ===<br />
Proportion of catchment with:<br />
* Land cover classes (Corine – Level 1)<br />
<br />
<br />
More details on the characterisation of catchments can be found in [[media:Deliverable2.1.pdf|chapter 5 of Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Catchment_characterisationCatchment characterisation2014-05-22T13:39:55Z<p>R.c.grabowski: Created page with "= Catchment characterisation = == Aim == Characterisation of the size, morphology, geological/soil and land cover controls on water (including groundwater) and sediment deliv..."</p>
<hr />
<div>= Catchment characterisation =<br />
<br />
== Aim ==<br />
Characterisation of the size, morphology, geological/soil and land cover controls on water (including groundwater) and sediment delivery to the drainage network.<br />
<br />
<br />
== Data layers and hydromorphologically relevant parameters==<br />
Essential GIS layers: DEM, geology (solid), land cover<br />
Optional GIS layers: soil permeability; geology (superficial). <br />
<br />
From these derive the catchment area, relief, extent of broad land cover types and extent of broad rock types. The latter can be subdivided according to their water holding properties (aquifers, aquicludes, aquifuges) and susceptibility to weathering / erosion.<br />
<br />
<br />
== Potential data sources ==<br />
* Digital Elevation Models [e.g. [http://epp.eurostat.ec.europa.eu/portal/page/portal/gisco_Geographical_information_maps/geodata/digital_elevation_model EU-GDEM]) <br />
* [http://ccm.jrc.ec.europa.eu/php/index.php?action=view&id=23 CCM2 River and Catchment Database (v2.1)]<br />
* [http://www.eea.europa.eu/data-and-maps/data/european-catchments-and-rivers-network Ecrins database]<br />
* [http://onegeology-europe.org/ One Geology Europe]<br />
* [http://eusoils.jrc.ec.europa.eu/library/esdac/OnLine_Data.cfm European soils data base]<br />
* [http://www.eea.europa.eu/data-and-maps CORINE land cover]<br />
* [http://forest.jrc.ec.europa.eu/download/data/ JRC Forest Cover Map]<br />
<br />
<br />
== Characteristics ==<br />
===Size, morphology and hydrological balance ===<br />
* Catchment area<br />
* WFD size category<br />
* Maximum, average and minimum elevation<br />
* Relative relief<br />
* WFD elevation zones<br />
* Average rainfall and runoff<br />
<br />
===Geology and soils ===<br />
Proportion of catchment with:<br />
* Exposed aquifers<br />
* Rock type classes<br />
* Soil permeability classes<br />
<br />
===Land cover ===<br />
Proportion of catchment with:<br />
* Land cover classes (Corine – Level 1)<br />
<br />
<br />
More details on the characterisation of catchments can be found in [[media:Deliverable2.1.pdf|chapter 5 of Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Region_characterisationRegion characterisation2014-05-22T13:36:33Z<p>R.c.grabowski: Created page with "=Region characterisation= == Aim == Broad description of the nature of the hydroclimate and natural land cover that are primary controls on all spatial scales of hydromorphol..."</p>
<hr />
<div>=Region characterisation=<br />
<br />
== Aim ==<br />
Broad description of the nature of the hydroclimate and natural land cover that are primary controls on all spatial scales of hydromorphological processes<br />
<br />
<br />
== Data layers and hydromorphologically relevant parameters==<br />
Climate / Biogeographic region <br />
<br />
<br />
== Potential data sources ==<br />
The European Environment Agency's [http://www.eea.europa.eu/data-and-maps/figures/biogeographical-regions-europe-2001 biogeographic region map]<br />
<br />
http://www.globalbioclimatics.org<br />
<br />
<br />
== Characteristics ==<br />
* Main river basin or district <br />
* Biogeographic region or ecoregion.<br />
<br />
<br />
More details on the characterisation of regions can be found in [[media:Deliverable2.1.pdf|chapter 5 of Deliverable 2.1]].</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-22T13:34:51Z<p>R.c.grabowski: </p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
<br />
<br />
=== Delineating the spatial units ===<br />
[[Media:Table 4.1Delineation.pdf | Table 4.1]] lists the hierarchy of spatial scales within the REFORM framework, provides a definition of each scale, the criteria that are used to delineate the spatial units, and some possible data sources to support delineation. <br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in Table 4.1. <br />
<br />
<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys, and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation|Region]]<br />
<br />
[[Catchment characterisation|Catchment]]<br />
<br />
[[Landscape unit characterisation|Landscape unit]]<br />
<br />
[[Segment characterisation|Segment]]<br />
<br />
[[Reach characterisation|Reach]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
[[Temporal analysis: Introduction | Introduction]]<br />
[[Temporal analysis: Field survey | Field survey]]<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
[[Temporal analysis: Historical | Historical information]]<br />
[[Temporal analysis: Palaeo | Palaeo techniques]] <br />
<br />
[[File:TimescalesApproaches.jpg]]</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Region_delineationRegion delineation2014-05-22T13:32:30Z<p>R.c.grabowski: /* Region */</p>
<hr />
<div>=Region=<br />
<br />
== Definition ==<br />
<br />
Relatively large area that contains characteristic assemblages of natural communities and species that are the product of broad influences of climate, relief, tectonic processes, etc.<br />
<br />
== Delineation ==<br />
<br />
At this scale, no delineation is strictly necessary, since most catchments will fall within a single biogeographic region (various regionalisations are available, but the European Environment Agency’s regionalisation is recommended as a general classification, and www.globalbioclimatics.org for a more detailed hierarchical classification). However some large or steep catchments may encompass more than one biogeographical region or subregion, and this information is likely to help to confirm delineation at the landscape unit scale, where factors within the catchment, such as topography, have a significant impact on biogeographical character.<br />
<br />
[[Hierarchical Framework and WFD |Why WFD ecoregions are not used to classify regions]]</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-22T13:03:38Z<p>R.c.grabowski: </p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
File:Delineation_diagram_new.png|Figure 2: Delineation of spatial units<br />
</gallery><br />
<br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
<br />
<br />
<br />
=== Delineating the spatial units ===<br />
[[Media:Table 4.1Delineation.pdf | Table 4.1]] lists the hierarchy of spatial scales within the REFORM framework, provides a definition of each scale, the criteria that are used to delineate the spatial units, and some possible data sources to support delineation. <br />
<br />
[[Media:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in Table 4.1. <br />
<br />
<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys, and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed.<br />
<br />
=== Characterising current condition===<br />
<br />
[[Region characterisation]]<br />
[[Catchment characterisation]]<br />
[[Landscape unit characterisation]]<br />
[[Segment characterisation]]<br />
[[Reach characterisation]]<br />
<br />
<br />
=== Characterising past condition and quantifying rates of processes ===<br />
<br />
Approaches, data sources and timescales of analysis of temporal change<br />
[[Temporal analysis: Introduction | Introduction]]<br />
[[Temporal analysis: Field survey | Field survey]]<br />
[[Temporal analysis: Remote sensing | Remote sensing]]<br />
[[Temporal analysis: Historical | Historical information]]<br />
[[Temporal analysis: Palaeo | Palaeo techniques]] <br />
<br />
[[File:TimescalesApproaches.jpg]]</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:Delineation_diagram_new.pngFile:Delineation diagram new.png2014-05-22T12:37:31Z<p>R.c.grabowski: </p>
<hr />
<div></div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-22T12:21:05Z<p>R.c.grabowski: /* Delineating the spatial units */</p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
</gallery><br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
[[File:Delineation_diagram_new.jpg|600px|center]]<br />
Figure 2: Delineation of spatial units<br />
<br />
<br />
=== Delineating the spatial units ===<br />
[[File:Table 4.1Delineation.pdf | Table 4.1]] lists the hierarchy of spatial scales within the REFORM framework, provides a definition of each scale, the criteria that are used to delineate the spatial units, and some possible data sources to support delineation. <br />
<br />
[[File:Table_4.2_Datasources.pdf | Table 4.2]] provides more information on the pan-European data sources referred to in Table 4.1. <br />
<br />
<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys, and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed<br />
<br />
=== Approaches, data sources and timescales of temporal analysis ===<br />
<br />
=== Spatial scales ===<br />
[[Region characterisation]]<br />
[[Catchment characterisation]]<br />
[[Landscape unit characterisation]]<br />
[[Segment characterisation]]<br />
[[Reach characterisation]]</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=Category:River_CharacterisationCategory:River Characterisation2014-05-22T12:20:11Z<p>R.c.grabowski: /* Delineating the spatial units */</p>
<hr />
<div>= River Characterization: Multi-scale Hierarchical Framework =<br />
<br />
<br />
<br />
== Background ==<br />
<br />
River characterisation is a process to determine the hydromorphological condition of a river. It investigates the current form and behaviour or a river, and how these have changed over time. <br />
<br />
Rivers naturally adjust over time, but human interventions in the channel, floodplain and wider landscape have dramatically altered their form and behaviour. Rivers have been straightened and deepened for navigation, dammed for milling and water supplies, and embanked for flood protection; floodplain have been converted to agriculture and are now home to millions of people; and in the wider landscape forests have been cleared, marshes drained and sediment sources blocked. These transitions have been ongoing for hundreds to thousands of years in Europe, and consequently few, if any, pristine rivers remain.<br />
<br />
Interventions that have occurred upstream, downstream or within the reach can influence its hydromorphology form and behaviour. For example, siltation in a lowland river reach can be caused by upstream changes in land use that increase the delivery of sediment to the channel (e.g. intensification of arable agiculture), impoundments downstream that produce a backwater effect that induces sediment deposition (e.g. dams and weirs), or modifications to the channel form or dimensions that reduce its capacity to transport sediment (e.g. channel deeping and widening). In addition, hydromophology responds in a delayed way to processes and interventions within the catchment. As a result, understanding hydromorphology at the reach scale requires an understanding of current and past processes and interventions at larger spatial scales. Without such a multi-scale understanding, management strategies are not fully informed and may not provide sustainable solutions.<br />
<br />
<br />
=== Link to ecology and river restoration ===<br />
<br />
A multi-scale approach to investigating hydromorphology inevitably focuses on geomorphological characteristics and the hydrological and geomorphological processes that influence those characteristics across time and space, but these are crucial for river ecology. Hydromorphological processes drive longitudinal and lateral connectivity within river networks and corridors, the assemblage and turnover of habitats, and the sedimentary and vegetation structures associated with those habitats. All of these processes and structures are relevant to the provision of habitats to support the entire life cycle of organisms including refugia, feeding, spawning etc. As a result, a process-based, multi-scale understanding of hydromorphology is essential for identifying degraded segments and reaches of river and for developing sustainable restoration approaches that are in sympathy with hydromorphological functioning from catchment to reach scales.<br />
<br />
<br />
== The Framework ==<br />
<br />
The multi-scale hierarchical framework has been developed to be a flexible, open-ended approach to hydromorphological assessment that is in line with the [http://ec.europa.eu/environment/water/water-framework/index_en.html Water Framework Directive]. As a result, the framework is compatible with WFD, but being process-based and multi-scale it allows practitioners to delve into further detail on the underlying drivers of hydromorphology. For more information on the links to WFD see [[Hierarchical Framework and WFD]]. <br />
<br />
The framework leads practitioners through a series of steps to delineate their river into spatial units; characterise the relevant hydrological, geomorphological and ecological charactersitics at each scale; and assess the current hydromorphological condition of the river and its sensitivity to change. It aims to make best use of currently available surveys (physical habitat, riparian habitat, morphological, hydrological regime and fish continuity, etc) and readily-available (mainly free) Pan-European data sets to guide users on:<br />
<br />
* What information is required at which spatial scale in the context of the data sets that are available and any new data that may be needed.<br />
* How the above information can be collected or generated, and how it can be analysed, in order to:<br />
* Describe and, crucially, explain variation in river character and behaviour within a catchment.<br />
* Provide users with a basis upon which they are able to understand past and present behaviour and predict how a particular reach might react to changes (e.g. removal of local engineering modifications, flow regime naturalisation, reinstatement of longitudinal sediment connectivity).<br />
* Allow users to define potential, site-specific, “reference” conditions against which current hydromorphological and ecological condition could be assessed.<br />
<br />
<br />
=== Rules of Engagement ===<br />
Some ‘rules of engagement’ need to be born in mind before embarking on the application of the methodologies proposed in this framework:<br />
# [[Rules of Engagement: 1 | Involve a professional geomorphologist]]<br />
# [[Rules of Engagement: 2 | Carry out a field survey]]<br />
# [[Rules of Engagement: 3 | View the framework as a guide to an approach rather than a recipe book]]<br />
# [[Rules of Engagement: 4 | Accept that true reference reaches devoid of human influence do not exist, and instead,]]<br />
# [[Rules of Engagement: 5 | Focus on hydromorphological processes.]]<br />
<br />
<br />
=== Hierarchy of spatial units ===<br />
The hierarchy of spatial units within which relevant properties, forms and processes can be investigated to understand and assess hydromorphology and its potential impact on ecology is presented in Figure 1. The units are arranged in decreasing over of size (indicative spatial scale) and persistence (indicative time scale):[[Region| region]], [[Catchment| catchment]], [[Landscape unit|landscape unit]], [[Segment| segment]], [[Reach | reach]] and [[Units| units]]. The reach is the key spatial scale at which the mosaic of features found within river channels and floodplains (i) responds to the cascade of influences from larger spatial scales and (ii) is influenced by interactions and feedbacks between geomorphic and hydraulic units and smaller elements such as plants, large wood and sediment particles within the reach.<br />
<br />
<br />
<gallery><br />
File:River characterisation hierarchy of spatial scales.png| Figure 1. Hierarchy of spatial scales for the European Framework, including indicative spatial dimensions and timescales over which these units are likely to persist.<br />
</gallery><br />
<br />
= Three stages of river characterization =<br />
<br />
<br />
== Stage 1: Delineation of spatial units ==<br />
<br />
=== General Guidance ===<br />
<br />
For catchment assessment and management purposes, the aim should be to subdivide the entire catchment into a complete set of units at all spatial scales from catchment to reach. In large catchments, this may not be possible, but it is necessary to subdivide the catchment to the scale of its major landscape units, after which representative subcatchments within each landscape unit can be analysed, delineating segments and reaches along the main channel and major tributaries for detailed analysis.<br />
<br />
For assessment of a particular reach or segment, a minimum assessment needs to focus on the specific reach or segment and larger spatial units that contain and are immediately upstream of the reach or segment under consideration<br />
<br />
[[File:Delineation_diagram_new.jpg|600px|center]]<br />
Figure 2: Delineation of spatial units<br />
<br />
<br />
=== Delineating the spatial units ===<br />
[[File:Table 4.1Delineation.pdf| Table 4.1]] lists the hierarchy of spatial scales within the REFORM framework, provides a definition of each scale, the criteria that are used to delineate the spatial units, and some possible data sources to support delineation. <br />
<br />
[[File:Table_4.2_Datasources.pdf|Table 4.2]] provides more information on the pan-European data sources referred to in Table 4.1. <br />
<br />
<br />
The following links provide summaries and detailed information on the delineation of units at each spatial scale<br />
<br />
''Region: '' [[Region| Summary]] - [[Region delineation | Detailed guidance]]<br />
<br />
''Catchment: '' [[Catchment| Summary]] - [[Catchment delineation| Detailed guidance]]<br />
<br />
''Landscape unit: '' [[Landscape unit|Summary]] - [[Landscape unit delineation| Detailed guidance]]<br />
<br />
''Segment: '' [[Segment| Summary]] - [[Segment delineation| Detailed guidance]]<br />
<br />
''Reach: '' [[Reach | Summary]] - [[Reach delineation| Detailed guidance]]<br />
<br />
== Stage 2: Characterisation of spatial units ==<br />
Characterisation of spatial units at the different scales attempts to draw together readily-available information, surveys, and data sets in ways that will promote understanding of the units and the linkages between them. Recommendations for characterisation take account of WFD requirements and make best use of existing pan-European and National data sets, including the outputs from physical habitat, riparian habitat, morphological, hydrological regime and fish continuity assessments, where they are available. Essential components of the characterisation are stressed<br />
<br />
=== Approaches, data sources and timescales of temporal analysis ===<br />
<br />
=== Spatial scales ===<br />
[[Region characterisation]]<br />
[[Catchment characterisation]]<br />
[[Landscape unit characterisation]]<br />
[[Segment characterisation]]<br />
[[Reach characterisation]]</div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:Table_4.2_Datasources.pdfFile:Table 4.2 Datasources.pdf2014-05-22T12:19:00Z<p>R.c.grabowski: </p>
<hr />
<div></div>R.c.grabowskihttps://wiki.reformrivers.eu/index.php?title=File:Table_4.1Delineation.pdfFile:Table 4.1Delineation.pdf2014-05-22T12:18:42Z<p>R.c.grabowski: </p>
<hr />
<div></div>R.c.grabowski