A new vulnerability function for debris flow - the importance of physical vulnerability assessment in alpine areas

Alpine hazards such as debris flows, landslides, snow avalanches and floods can cause apart from loss of life significant damage of the built environment and infrastructure. Since the possibilities for human intervention in the physical processes are limited risk reduction strategies additionally have to focus on physical vulnerability analysis, assessment and reduction of the elements at risk in order to reduce not only loss of life but also economic costs. Vulnerability assessment is a topic that is growing in importance also due to climate and environment change. Climate change influences the frequency and intensity of some events and the continuous development changes the spatial pattern of exposure and vulnerability. In this paper the growing importance of the assessment of physical vulnerability is highlighted through the introduction of a methodology to develop a vulnerability function for debris flows. The methodology is applied in South Tyrol, Italy. The final product can assist local authorities, emergency and disaster planners in decision making, cost benefit analysis of mitigation protection measures and assessment of potential costs of future events. Finally, recommendations for improved damage assessment that could enhance the quality of input data and thus the reliability of the function are made. The work presented in this paper has been carried out within the framework of an FP7 European project called MOVE (Methods for the Improvement of Vulnerability Assessment in Europe).