From Data to Decisions: Enhancing Avalanche Mitigation with Probability Mapping

In alpine regions, avalanches endanger infrastructure such as roads, ski slopes and buildings. Some of the avalanche paths cannot be protected permanently due to financial and topographic limitations. Therefore, local experts assess daily whether additional safety measures are required, such as temporary road or ski slope closures. To support this decision-making process, we produced avalanche probability maps that show potential daily avalanche runout areas and intensities. The probability maps are generated by running multiple avalanche simulations using realistic distributions of input parameters, such as release volume and erosion depth, to capture a representative range of possible scenarios and runouts. Additionally, we account for release probability by incorporating the predicted avalanche danger scale into the analysis. We aim to identify the minimum number of input parameters needed to meaningfully represent daily conditions. To perform the numerical simulations, we can apply models with varying levels of physical details. To evaluate the quality of the produced probability maps, we recalculated well-documented avalanche events from Switzerland, using meteorological station data from the mornings prior to the avalanche occurrence. We compare the resulting predictions to the measured outlines of the avalanche cores. This study demonstrates how real-time data on weather and snow conditions can be utilized effectively to provide practitioners with a quick overview on how far current avalanches can reach considering the current conditions to support their decision-making process.