Spatial evaluation of snow gliding in the Alps

Abstract

The slow downhill motion of snow on the ground, referred to as snow gliding, impairs afforestation, increases the predisposition for landslides, fosters winter soil erosion, and coincides with the occurrence of glide-snow avalanches. This study identifies areas with a high chance for severe snow gliding for an area covering >20,000 km2 in the Central and Eastern Alps. The Spatial Snow-Glide Model (SSGM) was used to map potential snow gliding areas (i.e. snow gliding distances). The results revealed 56% of the investigated area to be potential snow gliding areas. Nearly 2000 km2 (17%) were prone to snow gliding distances of >112 cm per winter period, indicating a high vulnerability for both glide cracks and glide-snow avalanches. Taking the inter-annual variability of winter precipitation into account, which turned out to be highest in the usually drier southern part, another 5690 km2 were found to have a high risk for snow gliding damages. For planning purposes of on-site mitigation measures the Guidelines to Identify Snow-Glide Areas (GISGA) were validated to corroborate the sequential application of SSGM and GISGA for comprehensive assessment of snow gliding at landscape scale. We conclude that the application of SSGM and GISGA provides an appropriate evaluation framework for regional stakeholders to implement adequate steps to prevent critical snow gliding.