The effect of spatial variations of snowpack properties on snow slope stability: a mechanically-based statistical approach

J. Gaume (1) , J. Schweizer (1) , A. van Herwijnen (1) , Guillaume Chambon (2) , Nicolas Eckert (2) , Mohamed Naaim (2)

1 Swiss Federal Institute for Forest, Snow and Landscape Research WSL
2 UR ETGR (ETNA) - Erosion torrentielle neige et avalanches

The spatial variability of snowpack properties has an important impact on snow slope stability and thus on avalanche formation. Hence, the determination of the link between these spatial variations and slope stability is very important, in particular for avalanche public forecasting. In this study, a statistical-mechanical model of the slab-weak layer (WL) system relying on random finite element simulation is used to investigate snowpack stability and avalanche release probability. This model accounts, in particular, for the spatial variations of WL mechanical properties and stress redistributions by elasticity of the slab. We show how avalanche release probability can be computed from release depth distributions which allow us to study the influence of WL spatial variations, slab depth and slope angle on slope stability. Finally, the importance of smoothing effects by slab’s elasticity is verified and the crucial impact of spatial variation characteristics on the so-called knock-down effect on slope stability is revisited using this mode.

Mots clés: SNOW AVALANCHE; AVALANCHE RELEASE; SLAB; WEAK LAYER; SPATIAL VARIABILITY; SLOPE STABILITY

Mots clés: AVALANCHE DE PLAQUE; ZONE DE DEPART D'AVALANCHE; LIGNE DE RUPTURE; VARIABILITE SPATIALE; STABILITE DES PENTES

Domaines: Sciences de l'environnement

J. Gaume, J. Schweizer, A. van Herwijnen, Guillaume Chambon, Nicolas Eckert, et al.. The effect of spatial variations of snowpack properties on snow slope stability: a mechanically-based statistical approach. International Snow Science Workshop (ISSW), Oct 2013, Grenoble – Chamonix Mont-Blanc, France. p. 57 - p. 60. ⟨hal-00951325⟩