Item: Evaluation of Protection Measures Against Avalanches in Forested Terrain
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Title: Evaluation of Protection Measures Against Avalanches in Forested Terrain
Proceedings: International Snow Science Workshop 2016 Proceedings, Breckenridge, CO, USA
Authors:
- Thomas Feistl [ Avalanche Warning Center Bavaria, Munich, Germany ]
- Armin Fischer [ Avalanche Warning Center Bavaria, Munich, Germany ]
- Peter Bebi [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Perry Bartelt [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
Date: 2016-10-02
Abstract: Small to medium sized avalanches release in forest gaps and open forest above roads and infrastructure in the Prealps regularly each winter. Avalanche bombing, silvicultural management and technical prevention measures such as glide snow tripods, snow fences and galleries can prevent road closure during the winter season. Besides historical data and expert knowledge, avalanche dynamics models are recently increasingly employed as additional danger assessment tool. Modelling small to medium sized avalanches in forested terrain requires high resolution digital terrain models and detailed process understanding concerning forest-avalanche interaction. Removal of snow by trees, energy loss through tree breakage and higher surface friction are the main processes that lead to earlier avalanche stopping. In this study we performed avalanche dynamics simulations for four well documented case study areas in the Bavarian Alps where forest influences avalanche runout distance. Wet and dry snow avalanche regimes were assumed for the south, west and north facing slopes, respectively. We found differing effect of forests on velocity and lateral spread of these avalanches depending on the flow regime, the forest stand characteristics and the underlying terrain features. Whereas technical avalanche defense structures to hinder snow gliding and support tree re-growth are the most promising courses of action in three cases, a dam to protect the road is the most effective measure for the fourth slope. These case studies demonstrate how avalanche dynamics models can support local authorities in facilitating the planning of optimal avalanche prevention measures.
Object ID: ISSW16_P1.12.pdf
Language of Article: English
Presenter(s):
Keywords: avalanche, forest, public safety, modelling
Page Number(s): 561-568
Subjects: forest avalanche public safety modelling
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