Item: The Systematic Snow Cover Analysis: a Practical Tool for Interpreting and Assessing Slope Stability
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Title: The Systematic Snow Cover Analysis: a Practical Tool for Interpreting and Assessing Slope Stability
Proceedings: International Snow Science Workshop 2014 Proceedings, Banff, Canada
Authors:
- Georg Kronhaler [ Bavarian Avalanche Warning Service, Munich, Germany ]
- Christoph Mitterer [ Bavarian Avalanche Warning Service, Munich, Germany ] [ WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland ]
Date: 2014-09-29
Abstract: Avalanche professionals rely often on direct snowpack information to determine slope stability or assess the avalanche danger of a specific site or avalanche path. However, the interpretation of snowpack observations is not always unambiguous. Previously presented interpretation schemes of direct snowpack information (e.g. snow profiles) require a full snow stratigraphy with a distinct stability test, which makes them often unattractive among practitioners – mainly due to lack of time. We will present a fast and systematic approach on how to reliably interpret snowpack observations and judge the release probability of a single slope based on a stability test, the characteristics of the slab and the weak layer stratigraphy. For the winter seasons 2008-2009 to 2010-2011, various observers performed snow profiles including a stability test and evaluated avalanche release probability. With a classification tree, we investigated which properties of the snow profile and the test led to which avalanche danger assessments. The tree revealed that situations with high release probability had always a prominent weak layer, a sudden or planar fracture and low test scores. The decision path of the resulting tree was then applied and tested using a second, independent data set that included objective measures of stability, i.e. skier-triggered avalanches, shooting cracks or whumpfs. The predictive skills of the tree were reasonable, but significantly improved if more information on the slab, i.e. hardness, and weak layer stratigraphy were introduced. The results were encouraging and will help practitioners to assess slope stability more reliably.
Language of Article: English
Presenters:
Keywords:
Page Number(s): 815-819
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Digital Abstract Not Available
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