Modeling of River Velocity, Temperature, Bed Deformation and its Effects on Rainbow Trout (Oncorhynchus mykiss) Habitat in Lees Ferry, Colorado River

Document Type: Original Research Paper

Authors

1 Institute of Hydraulic and Water Resources Engineering, Technical University of Munich, Arcisstr 21, Germany

2 Civil Engineering Department, National Institute of Technology, Kurukshetra, India

Abstract

Quantification of the habitat available for fish species named Rainbow Trout (Oncorhynchus
mykiss) were evaluated in Lees Ferry, Colorado River using water depth, water temperature, sediment transport,
flow velocity in 2004 as environmental index. For the flow velocity and temperature distribution calculations
in the river, the Navier-Stokes equation and energy conservation equations with finite volume approach has
been employed. Sediment transport and river bed deformation in Lees Ferry were also calculated based on
Engelund-Hansen equations. The suitability index (SI) curves based on these four biological, ecological and
hydraulic factors were obtained and fish habitat suitability function was established. The HSI (habitat suitability
index), WUA (weighted useable area), OSI (overall suitability index) of the fish species were quantitatively
calculated using SI curves coupled with habitat suitability function. The effects of these variables on the Lees
Ferry river areas were analyzed. The results showed that the model system can correctly represent the
Rainbow Trout living situation. The WUA and OSI are generally low in Less Ferry and the proportions of high
quality of OSI (HSI ) are even less which is in accordance with the real situation. The results also
revealed that there is a nonlinear relationship between flow discharge and suitable habitat areas.

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