A GIS Tool for Fish Habitat Modeling

An ArcGIS fish habitat modeling tool is developed to model the extent of fish habitat under different flow conditions. The study of the impact of change in flow on availability of fish habitat in river channels involves biological sampling, river surveying and hydraulic modeling. Biological sampling seeks to associate fish species with the hydraulic habitat they utilize and the habitat conditions are defined in terms of depth and velocity. The velocity and water depth for different flow rates are obtained by using a two-dimensional hydraulic model. The fish habitat modeling tool combines the results of the hydraulic model and the biological sampling statistics to determine the spatial extent of available hydraulic mesohabitat and the available hydraulic habitat for individual fish species at each of a number of different flow rates. The application of the habitat modeling tool is demonstrated by applying it to a short reach of the lower Brazos River in Texas