Difference between revisions of "Reach"

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(Created page with "=Reach= ==General description== ==Case studies where this River Characterisation is relevant== <Forecasterlink type="getProjectsForRt" code="5"/> ==Tools where this River C...")
 
 
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=Reach=
 
=Reach=
  
==General description==
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== Definition ==
  
==Case studies where this River Characterisation is relevant==
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Section of river along which boundary conditions are sufficiently uniform that the river maintains a near consistent internal set of process-form interactions. (A river segment can contain one to several reaches). As a general rule, the length of a reach should not be smaller than 20 times the mean channel width, although shorter reaches can be defined where local circumstances are particularly complex.
  
<Forecasterlink type="getProjectsForRt" code="5"/>
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== Delineation criteria ==
==Tools where this River Characterisation is relevant==
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* Channel morphology (particularly planform)
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* Floodplain features 
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* Artificial discontinuities that affect longitudinal continuity (e.g. dams, major weirs / check dams that disrupt water and sediment transfer)
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* River confinement
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== Methods and data sources==
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Segments are subdivided into reaches by visual interpretation of consistent river and floodplain (bio) geomorphic pattern using
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* Google Earth
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* Orthophotos
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* Multi-spectral remotely-sensed data
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* Lidar data
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(Field reconnaissance can provide useful confirmation / additional data)
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<gallery>
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File:Frome_reach_deline.jpg|The River Frome is delineated into 15 reaches based on valley confinement, river planform and the presence of major weirs.
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File:Frome_reach_type.jpg|The River Frome has sinuous, meandering and anabranching reaches.
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</gallery>
  
<Forecasterlink type="getToolsForRt" code="5"/>
 
==Other relevant information==
 
  
 
  [[Category:River Characterisation]] [[Category:Reach]] [[Category:Reach]]
 
  [[Category:River Characterisation]] [[Category:Reach]] [[Category:Reach]]

Latest revision as of 15:33, 7 January 2019

Reach

Definition

Section of river along which boundary conditions are sufficiently uniform that the river maintains a near consistent internal set of process-form interactions. (A river segment can contain one to several reaches). As a general rule, the length of a reach should not be smaller than 20 times the mean channel width, although shorter reaches can be defined where local circumstances are particularly complex.

Delineation criteria

  • Channel morphology (particularly planform)
  • Floodplain features
  • Artificial discontinuities that affect longitudinal continuity (e.g. dams, major weirs / check dams that disrupt water and sediment transfer)
  • River confinement

Methods and data sources

Segments are subdivided into reaches by visual interpretation of consistent river and floodplain (bio) geomorphic pattern using

  • Google Earth
  • Orthophotos
  • Multi-spectral remotely-sensed data
  • Lidar data

(Field reconnaissance can provide useful confirmation / additional data)