The objective of the NRP 31 is the detailed study of the mechanisms and consequences of future climate changes in the Swiss environment, and the resulting interactions between climate, the water cycle, natural hazards, ecosystems and society. This programme should help improve our understanding of the response of the environment to abrupt short-term climatic events and to long-term climate changes, and provide answers to economic and political decision making. The emphasis of research will be on processes acting on the regional scale, especially in the Swiss Alps. A particular attention will be given to interdisciplinary studies. There is an attempt to bring together specific projects in especially sensitive geographical test-zones, as representative as possible of Swiss conditions. Numerous applications of the research supported by NRP 31 are envisaged, results will be continuously subject to detailed and realistic assessment. As an example of this approach, the flood events which affected the town of Brig in the Swiss Alps the 24 September 1993, will be presented and discussed in detail.