1D analytical models for gradually-varied flow

1D analytical models for gradually-varied flow

Type

Hydromorphological models

Basic principles

Fundamental equations for conservation of water mass and water flow momentum under the assumption of steady flow, spatially averaged over cross-section segments and time-averaged over all turbulent fluctuations.

Outputs

Flow velocities, water depths, water levels, flow shear stresses.

Rivertypes

• Reach
•    Reach

Related Pressures

• Surface water abstraction
• Groundwater abstractions
• Hydropeaking
• Sediment discharge from dredging
• Reservoir flushing
• Hydrological regime modification
• Interbasin flow transfers
• Discharge diversions and returns
• Colinear connected reservoir
• Artificial barriers downstream from the site
• Artificial barriers upstream from the site
• Alteration of instream habitat
• Sand and gravel extraction
• Sedimentation and sediment input
• Embankments, levees or dikes
• Loss of vertical connectivity
• Impoundment
• Alteration of riparian vegetation
• Channelisation / cross section alteration
• Other pressures

Related Measures

• Improve/Create water storage
• Reduce water consumption
• Increase minimum flows
• Recycle used water
• Improve water retention
• Reduce surface water abstraction with return
• Water diversion and transfer
• Reduce surface water abstraction without return
• Reduce groundwater extraction
• Reduce anthropogenic flow peaks
• Modify hydropeaking
• Shorten the length of impounded reaches
• Increase flood frequency and duration in riparian zones or floodplains
• Favour morphogenic flows
• Link flood reduction with ecological restoration
• Ensure minimum flows
• Manage aquatic vegetation
• Establish environmental flows / naturalise flow regimes
• Facilitate downstream migration
• Manage sluice and weir operation for fish migration
• Remove barrier
• Install fish pass/bypass/side channel for upstream migration
• Modify culverts, syphons, piped streams
• Fish-friendly turbines and pumping stations

Useful references

Theoretical background

Chow V.T. (1959): Open-channel hydraulics. McGraw-Hill, New York, 680 pp.

Henderson F.M. (1966): Open channel flow. Macmillan, New York, 522 pp.