Quantifying directional roughness as a combination of terrain and surface properties in snow avalanche release areas

Innsbruck

2022

1 S.

Sonderdruck

13071S

40003737

Topography and total roughness of the terrain, which is composed of surface roughness (approximately 1 m-scale) and terrain roughness(approximately 5-10 m-scale), influence the distribution of snow as well as snowpack properties. Down woody debris such as logs, stumps,branches or root plates as well as rocks and other obstacles in the terrain cause surface roughness. These features disturb the snowpack andcan influence avalanche formation by creating an inhomogeneous and noncontinuous snow stratigraphy and by anchoring the snowpack. Theuneven distribution/redistribution of snow due to wind will promote inhomogeneous snow depths and snow stratigraphy, which can disrupt thecontinuity of a potential weak layer or sliding surface. Roughness elements distributed along the fall line can therefore help anchoring thesnowpack to the ground as a snow supporting structure. By accounting for the roughness in the direction of the fall line of the terrain, it might bepossible to further refine the delineation of potential avalanche release areas.