Habitat - A program system for physical fish habitat assessment

Computer models for quantification of impacts of river regulations onfish habitat has been applied to several projects in Norway and abroad over t last decade. The increased availability of advance hydraulic simulation engines has greatly increased the detail in which we can describe the spatial distribution of physical variables,and this is now st arting to influence the methods used for classification of fish habitat. To be able to handle the complex taskof model construction and integration of many new methods, the Habitat program system has been completely redesigned to handle frequent updates and to offer a flexible way of combining hydraulic and biological modelling tools. This pa per describes the design of the Habitat model, and it outlines the hydraulic and biological tools now available in the system.