Item: ON THE INFLUENCE OF SNOW DEPTH ON SURFACE SHAPE AND ROUGHNESS IN THE RELEASE AREAS OF OBSERVED SKIER-TRIGGERED AVALANCHES
-
-
Title: ON THE INFLUENCE OF SNOW DEPTH ON SURFACE SHAPE AND ROUGHNESS IN THE RELEASE AREAS OF OBSERVED SKIER-TRIGGERED AVALANCHES
Proceedings: International Snow Science Workshop 2024, Tromsø, Norway
Authors:
- Andreas Stoffel [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ] [ Climate Change, Extremes and Natural Hazards in Alpine Regions Research Center CERC, Davos, Switzerland ]
- Stephan Harvey [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Yves Bühler [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ] [ Climate Change, Extremes and Natural Hazards in Alpine Regions Research Center CERC, Davos, Switzerland ]
Date: 2024-09-23
Abstract: The snow-covered winter surface differs significantly from its snow-free equivalent due to the smoothing caused by progressive snow accumulation and erosion. This smoothing effect becomes more pronounced as the absolute snow depth increases. However, variations in accumulation, settling and redistribution occur in complex mountain terrain. The spatial variability of snow depth plays a crucial role in the formation and dynamics of snow avalanches. Surface shape and roughness serve as established metrics to assess the effect of snow on terrain. In this study, we investigate snow surface smoothing within the release areas of typical skier-triggered avalanches observed in the vicinity of Davos, Switzerland. We analyze the release areas of nearly 2000 avalanches of class size 2 to 3, using high spatial resolution (0.5 m) annual snow depth maps recorded during the peak of winter over 6 years and covering an area of 275 km2. These avalanche release areas are grouped according to their main terrain shape. Within each group, the influence of snow depth on surface shape and roughness is assessed. Finally, we investigate the effect of different DEM resolutions on the terrain smoothing factor and analyze the intra-annual consistency of the terrain smoothing. For the first time, we assess the role of snow depth on surface shape and surface roughness in avalanche release areas over a large sample size and a large area. We find strong agreement in the intra-annual terrain smoothing behavior despite significant differences in mean snow depths observed over the study period, ranging from 0.73 m in 2023 to 2.2 m in 2019.
Object ID: ISSW2024_P9.1.pdf
Language of Article: English
Presenter(s):
Keywords: Snow depth, surface shape, surface roughness, snow avalanches, remote sensing
Page Number(s): 1256 - 1262
-