Author(s): C. Katopodis; H. Ghamry
Linked Author(s):
Keywords: Hydraulics; Numerical modeling; Instream flow; Fish habitat; Weighted usable are
Abstract: Fish habitats represent some of the most difficult biological, topographic and hydrodynamic phenomena to evaluate and simulate in detail. However, computational advances may now allow reasonable and accurate hydraulic and biological model results in such challenging circumstances. The purpose of this study was to evaluate the suitability of habitat throughout a range of flows by combining detailed hydraulic modeling with speciesspecific habitat suitability criteria that can be used to protect or enhance fish life in the Assiniboine River, Manitoba, Canada. The two-dimensional finite element model, the RIVER2D (www. river2d. ca), was used to achieve these goals. This model uses the Characteristic Dissipative Galerkin Finite Element computational technique, which allows for the simulation of shock and disturbance propagation. Four reaches or study sites on the Manitoba portion of Assiniboine River were investigated. Model predictions were compared to detailed representative field measurements. The comparisons showed that the model performs reasonably well. The hydrodynamic results, coupled with biologically significant suitability metrics, were used to determine changes in fish habitat areas with discharge. This ichthyohydraulic simulation process provides water management guidance. Depending on the Assiniboine site selected, instream flows for fish habitat appeared to be in the range of 2-5 m3/s as a minimum, and 16-30 m3/s as an optimum.
Year: 2003