Natural Hazards and Earth System Science www.nat-hazards-earth-syst-sci.net 1561-8633 1684-9981 5 6 2005 10.5194/nhess-5-893-2005 http://www.nat-hazards-earth-syst-sci.net/5/893/2005/ http://www.nat-hazards-earth-syst-sci.net/5/893/2005/nhess-5-893-2005.html http://www.nat-hazards-earth-syst-sci.net/5/893/2005/nhess-5-893-2005.pdf 893 901 2005-11-09 The long-term development of avalanche risk in settlements considering the temporal variability of damage potential S. Fuchs M. Keiler A. Zischg M. Bründl alpS Centre for Natural Hazard Management, Innsbruck, Austria Department of Geography and Regional Research, University of Vienna, Austria Geo Information Management, Gargazzone, Italy WSL Swiss Federal Institute for Snow and Avalanche Research SLF, Davos, Switzerland Recent studies on the avalanche risk in alpine settlements suggested a strong dependency of the development of risk on variations in damage potential. Based on these findings, analyses on probable maximum losses in avalanche-prone areas of the municipality of Davos (CH) were used as an indicator for the long-term development of values at risk. Even if the results were subject to significant uncertainties, they underlined the dependency of today's risk on the historical development of land-use: Small changes in the lateral extent of endangered areas had a considerable impact on the exposure of values. In a second step, temporal variations in damage potential between 1950 and 2000 were compared in two different study areas representing typical alpine socio-economic development patterns: Davos (CH) and Galtür (A). The resulting trends were found to be similar; the damage potential increased significantly in number and value. Thus, the development of natural risk in settlements can for a major part be attributed to long-term shifts in damage potential.