Climate change impacts on snow avalanche risk in alpine regions

Abstract

<p>Various studies show that changes in the climate system, such as temperature rise and extreme precipitation events, strongly influence gravity driven hazards. Within the  research program "Climate Change Impacts on Alpine Mass Movements'', we develop a framework to model mass movement risk altered by climate and socio-economic drivers. In a first approach, we've modeled snow avalanche risk in Switzerland for the current climate situation and three avalanche hazard scenarios. For each of these scenarios we've considered different 3-day increases in snow height for avalanche formation, derived from meteorological stations. For the modelling we've applied the RAMMS::LSHIM Large Scale Hazard Indication Mapping algorithm combining the delineation of potential release areas from a high-resolution terrain model with a forest layer to depict the spatial distribution of avalanche impact for each of the chosen scenarios. <br>To model possible climate change effects on snow avalanche hazard, we use down-scaled data from the CH2018 climate change scenarios as input for the  model "SNOWPACK''. The so-derived changing avalanche hazard disposition is simulated with the RAMMS::LSHIM method and risks are analysed with the probabilistic, Python-based risk assessment platform CLIMADA using high resolution building layers to identify monetary assets and assign vulnerabilities. The results are spatio-temporally explicit risk maps, depicting changes of snow avalanche risks based on the combination of exposure and vulnerability information. These maps allow for the appraisal of appropriate risk management options and thereby contribute to decision support and highlight areas where adaptation measures to climate change might be needed.</p>