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| Titel |
Quantification of basal friction for technical and silvicultural glide-snow avalanche mitigation measures |
| VerfasserIn |
T. Feistl, P. Bebi, L. Dreier, M. Hanewinkel, P. Bartelt |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Sciences ; 14, no. 11 ; Nr. 14, no. 11 (2014-11-07), S.2921-2931 |
| Datensatznummer |
250118745
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| Publikation (Nr.) |
 copernicus.org/nhess-14-2921-2014.pdf |
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| Zusammenfassung |
| A long-standing problem in avalanche engineering is to design defense structures and manage
forest stands such that they can withstand the forces of the natural snow
cover. In this way, glide-snow avalanches can be prevented. Ground friction
plays a crucial role in this process. To verify existing guidelines, we
collected data on the vegetation cover and terrain characteristics of 101
glide-snow release areas in Davos, Switzerland. We quantified the Coulomb
friction parameter μm by applying a physical model that
accounts for the dynamic forces of the moving snow in the stauch zone. We
investigated the role of glide length, slope steepness and friction in
avalanche release. Our calculations revealed that the slope angle and slab
length for smooth slopes correspond to the technical guidelines for defense
structure distances in Switzerland. Artificial defense structures, built in
accordance with guidelines, prevent glide-snow avalanche releases, even when
the terrain is smooth. Slopes over 40 m in length and 45° in
steepness require a ground friction of μm = 0.7 corresponding
to stumps or tree regeneration to ensure protection. Forest management
guidelines that define maximum forest gap sizes to prevent glide-snow
avalanche release neglect the role of surface roughness and therefore
underestimate the danger on smooth slopes. |
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