SAMOS (Snow Avalanche Modelling and Simulation) is an advanced tool for hazard mapping and is already in operational use at the Forest Technical Service for Avalanche and Torrent Control in Austria. The SAMOS-Software includes a Pre-/Postprocessor, which is an adaption of the FIRE V.7 Pre-/Postprocessor, and a CFD-simulation-program based on the FIRE V.7 solver. Snow avlanches typically comprise two-layers: a powder snow layer on top of a dense-flow-layer. The powder snow layer is computed in 3 D with the FIRE solver, the dense-flow-layer is computed in 2 D with an embedded shallow-water-model, specifically developed for SAMOS. Case studies with observed and well documented (artifically or naturally released) avlanches are used to check the reliability of the model. Furthermore enhancements of the model are based on these studies. Simulation results of avlanches in the Alps (Austria, Wolfgruben avalanche, St. Anton a/A, Tyrol; Swiss, Creta Besse avalanche, Vallee de la Sionne, Canton du Valais) and Norway (Ryggfonn) are presented in this paper. The results are compared with observed (measured, mapped) parameters such as velocity, deposit distribution, deposit depth or impact pressure.
