Item: Winter Terrain Roughness as a New Parameter to Define Size and Location of Avalanche Release Areas
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Title: Winter Terrain Roughness as a New Parameter to Define Size and Location of Avalanche Release Areas
Proceedings: International Snow Science Workshop Grenoble – Chamonix Mont-Blanc - October 07-11, 2013
Authors:
- Jochen Veitinger [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- B. Sovilla [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- R. S. Purves [ Department of Geography, University of Zurich, Zurich, Switzerland ]
Date: 2013-10-07
Abstract: Location and size of avalanche release areas are crucial inputs in modelling of avalanche dynamics as, together with fracture depth, they determine the initial avalanche volume. One difficulty in estimating avalanche release areas is that they vary in location and size within the same topographical basin due to variation in snow cover distribution. During the snow accumulation season, terrain features successively disappear leading to increasingly homogeneous deposition patterns during storm events and, thus, to a progressive smoothing of the terrain surface. These changing deposition patterns might therefore explain the differences in release areas. To characterize the smoothing effect of snow on terrain we use the concept of roughness. Roughness is calculated for several snow surfaces and their corresponding underlying terrain. To this end, elevation models of winter and summer terrain are derived from high-resolution measurements performed by airborne LIDAR. The winter datasets correspond to snow cover scenarios with varying snow depths ranging from 1m to 4m. For one scenario, six avalanches were artificially triggered and an additional laser scan was performed after the releases. We show that for both summer and winter surfaces, low roughness values are organized in clusters. Further, the clusters obtained from the snow scenario with avalanches are able to reproduce location and size of the observed release areas.
Language of Article: English
Presenters: Unknown
Keywords: roughness, slab avalanche, snow distribution
Page Number(s): 703-706
Subjects: avalanche release zones slab avalanche avalanche terrain
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Digital Abstract Not Available
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