By having developed the habitat model HM-AF (Habitat Model – Adequate Fidelity), one of the analysis methods based on GIS, it is now possible to further use the results of hydraulic modelling and by that to achieve a synergetic effect. These results shall lie on an accuracy scale, providing an overview of all the parameters in a stretch of a river and serving as a decision-making aid.

HM-AF is applied to analyse fish species in a stretch of water. The results from this analysis are then combined with results of 2D-discharge modelling with habitat requirements (preferences) of the species and their development stages. Our model shows preferences for water depth, flow velocity, and bed material. If required, the evaluation of the habitat also includes the understory offer.

Results are as follows:

• Habitat suitability - Suitability Index (SI): specifies the match of a discharge situation in a defined stretch of water with the preferences of the analysed fish species on a scale from 0 (not suitable) to 1(extremely suitable).

• Weighted usable area (WUA): equates to the habitat range in a stretch of water depending on the discharge situation.

• Graphic and tabular analysis of the results

The habitat model HM-AF has already been applied successfully and will be further improved and optimized. We plan to implement the programming of a graphic user interface in the year 2010.