EVHA, A WINDOWS SOFTWARE FOR FISH HABITAT ASSESSMENT IN STREAMS

EVHA is devoted to the simulation of fish habitat in streams. It essen tially uses a graphical approach. EVHA includes modules for the valida tion of topographic data and for the calibration of the hydraulic mode l. After dealing with these, the user considers the habitat or physica l variables according to the four representations proposed discharge c urves, maps, cross sections, and longitudinal profiles. The text of th e calculated data can be read on separate Windows, and both graphs and data can be saved in Windows environment, through output files compat ible with standard software or through the clipboard. Three habitat va riables, the Weighted Usable Area (WUA), the 100 m normalized WUA, and the habitat value, but also wetted surfaces, depth, velocity and Frou de number can be evaluated for each measurement point or averaged to t he scale of the cross section, of the morphological unit, or of the wh ole site. User's preference curves can be employed beside EVHA's ones.