Simulating High-Flow Effects (HFE) on river deformation and rainbow trout (Oncorhynchus mykiss) habitat

After the Glen Canyon Dam (Arizona, USA) has been built, some artificial High Flow Effects (HFE) were generated which dramatically altered the physical environment (e. g. discharge, water temperatures, and sediment transport) in Colorado River. Those changes especially the High Flow Effects (HFE) might positively or negatively alter the rainbow trout (Oncorhynchus mykiss) habitat in the clear tail water reach below Glen Canyon Dam. This paper proposed a habitat model to evaluate the short term high flow effects on the river hydraulic, sediment transport as well as rainbow trout habitat of the study region. Firstly, based on the classic CFD (Computational Fluid Dynamics) model and heat transfer equation for hydraulic simulation, three hydraulic factors including water depth, velocity and temperature distribution were simulated. Secondly, the rainbow trout preference curves were obtained based on flow velocity, water depth and temperature distribution. Thirdly, the habitat suitability equation was developed and the fish habitat model was also created based on the equation used to simulate the rainbow trout habitat situation in short time high flow effects. Finally, the WUA (Weighted usable area) and OSI (Overall suitability index) of fish species were quantitatively calculated to evaluate the sensitivity of the short time high flow. This approach helps understanding the river hydraulic change, sediment transport and fish habitat suitability index in situations of high flow effects.