Snow gliding and avalanches in a south-facing larch stand : Soil-Vegetation-Atmosphere Transfer Schemes and Large-Scale Hydrological Models

Washington D.C.

2001

S. 1-4

Bandaufführung

9394S

72131

Release zones of avalanches are common in forests sites, especially in low density stands near the timberline. Observations showed that slab avalanches (caused by weak layers like surface or depth hoar), as well as glide avalanches, are possible in larch stands with a low canopy density. The main condition for the formation of glide avalanches in forest sites is a strong increase in the rates of snow gliding. This investigation shows that snow gliding is strongly influenced by the forest canopy. Less dense forest canopies were associated with higher snow glide rates. The total distance of snow gliding in the dense forest did not exceed 100 mm; however, total gliding in forest clearings reached values up to 1700 mm. Gliding is more frequent in winter periods with deep snow and less frequent in those years where the snow depth was below average. Snow gliding in forests increases over February, March and April; but there is no gliding in January because of low snow temperature.