Potential slab avalanche release area identification from estimated winter terrain: a multi-scale, fuzzy logic approach

Abstract

Abstract. Avalanche hazard assessment requires a very precise estimation of the release area, which still nowadays depends to a large extent on expert judgement of avalanche specialists. Therefore, a new algorithm for automated identification of potential avalanche release areas was developed. It overcomes some of the limitations of previous tools, which are relatively scarcely applied in hazard mitigation practice. By introducing a multi-scale roughness parameter, fine-scale topography and its attenuation under snow influence is captured. This allows the assessment of snow influence on terrain morphology and, consequently, potential release area size and location. The integration of a wind shelter index enables the user to define release area scenarios as a function of the main wind direction or single storm events. A case study illustrates the practical usefulness of this approach for the definition of release area scenarios under varying snow cover and wind conditions. The validation with historical data demonstrated an improved estimation of avalanche release areas, in particular for more frequent avalanches; however, the application of the algorithm as a forecasting tool remains limited, as snowpack stability is not integrated. Future research activity could therefore focus on the coupling of the algorithm with snowpack conditions.