Item: Modelling Small and Frequent Avalanches
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Title: Modelling Small and Frequent Avalanches
Proceedings: International Snow Science Workshop 2014 Proceedings, Banff, Canada
Authors:
- Lisa Dreier [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Yves Bühler, [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Walter Steinkogler [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Thomas Feistl [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Marc Christen [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Perry Bartelt [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
Date: 2014-09-29
Abstract: Numerical simulation tools are commonly used to model extreme events, that is avalanches with return periods of 30 years or more. Recently, a new demand has arisen in avalanche engineering practice: the modelling of "small", frequent avalanches. These avalanches with release volumes between 1,000 - 10,000 m3 often threaten traffic infrastructure and ski runs. In this paper we apply a new physical avalanche model to simulate "small", frequent avalanches using high spatial resolution DEM data. The case studies consist of avalanches documented in the Swiss accident database. For these avalanches, we have reliable data concerning release location, fracture height, run-out distance and snow temperatures at time of release. Photographs provide information regarding snow cover entrainment. A set of model parameters was determined which depends on the avalanche flow type and hence on snow temperature. We explicitly avoided changing parameters according to avalanche size. The avalanches were simulated according to the temperature classification scheme we established. We analyzed the impact of the re-lease location, release height and entrainment on the avalanche run-out. Our results highlight the importance of release zone definition, release height, snow temperature and the difference between summer and winter terrain models for small-scale avalanches. We plan to apply the findings of this study to produce a small-scale avalanche simulation tool intended to support persons in charge of ski resorts and traffic infrastructure.
Object ID: ISSW14_paper_P2.06.pdf
Language of Article: English
Presenter(s):
Keywords: avalanche dynamics, avalanche mitigation, hazard assessment, snow entrainment, snow temperature.
Page Number(s): 692-699
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