Quantitative risk analysis for evaluation of avalanche protection projects

Abstract

Questions on optimum protection measures have always been bound to economic considerations. This involves a comprehensive investigation and analysis of the effect of avalanche protection measures with an appropriate concept of risk, including the avalanche danger area and land use of the area. Technical and economic methods and analysis are applied in methodical procedures in order to arrive at an assessment model for avalanche protection projects. From the technical point of view, the application of general risk analysis methodology and its adaptation to specific circumstances related to avalanche hazards are in the foreground. The quantitative risk magnitudes are supplemented by the aspects of risk awareness, in particular of risk acceptance and risk aversion. The avalanche risk of specific protection projects in the sense of an expected annual value of damage is calculated as part of the total potential damage. The result of this risk analysis is shown in a quantitative risk - diagram with the outset risk without safety measures, the remaining risk and the risk reduction. By comparing the annual costs for measures and the expected risk reduction, it is possible to make comparisons between measures with a short-term and long-term effect. The targeted project selection for this paper takes the expected variability of the efficiency into account in order to be able to define the economical limits. It is also possible to deduce marginal costs which, in the past, were applied to prevent a statistical death occurrence.