The abiotic circumstances in Austrian watercourses are altering because of climate change. Rising air temperatures bring about an increase in water temperatures, which in turn influences strongly the fish fauna and its living environment in watercourses, where the fishing districts are located. Salmonids, originated in cold water, whose districts are a valuable ecological and socio-economic resource for the fishing industry, are affected first. The digital federal state fishing cadastre is the most important management tool of the five Lower Austrian fishing district associations and has to include a cartographic image of the district areas, due to the existing fishing law. Until now, the fishing atlas, an analogue cartography, has been used. In this thesis, the areas of all 452 Lower Austrian fishing districts are digitalised by means of geographical information systems (GIS). Based on this, fish-ecological data for 90% of the fishing districts are collected and analysed. The cold water preferring Salmonids reveal currently a potential habitat in 64% of the districts, which conforms to approximately 5.700km of watercourses. At the moment ca. 2.350km of the Epi- and Metarhithral regions feature a mean air temperature in July of 13C to 19C. An increase in air temperature of 4C would represent a decline of 65% of river reaches in the trout-region. In the future, the collected data shall serve as a basis for questions of the fishing industry concerning the impacts of climate change.