K. Kleemayr, m. Platzer, s. Simma & G. Volk (Zentrum fuer Geoinformationswessen, 

Daenenstrasse 6, A-1990, Wien, Austria)

An energy line based avalanche run out model (ELBA) combining statistical and physically based components has been implemented into a raster GIS. Due to the fact that the snow physical processes taking place in an avalanche cannot be described yet the energy losses of an avalanche on its path down the slope are calculated stochastically by adapting the energy line concept. In contrast the information of the terrain where an avalanche is taking place can be quite detailed since we can use digital elevation models. Therefore the effects of the terrain on the flowpath of an avalanche can be modelled in a deterministic way by applying the laws of linear momentum on a geometrically exact flow algorithm in a grid based model. The model has been tested in Austria and Northern Italy. The results exhibited very good coincidence with historical data concerning the runout length as well as the trajectories of the simulated avalanches.