The application of the SAMOS - Model for avalanche control : Advanced Techniques for the Assessment of Natural Hazards in Mountain Areas

2000

S. 6

Bandaufführung

75369

Changes in economic and social behaviour of the west-European societies led to an increasing and expanding of tourist recreation areas and ski resorts. As a consequence of that development traffic infrastructures, settlements and also human lives got more and more threatened by avalanches. In this respect, the knowledge about the avalanche formation, its dynamics and its behaviour in the whole catchment is of extreme importance. For this reason the SAMOS (Snow Avalanche Modelling and Simulation) model was developed for the Ministry for Agriculture and Forestry of Austria in cooperation with the Austrian Torrent and Avalanche Control, the Research Station for comubstion Machines (AVL) in Graz, the Austrian Institute for Avalanche and Torrent Research (FBVA) and the Department of Fluid Dynamics and Heat Transfer, University of Vienna. The so called "Catastrophic-Avlanches" are avalanches with a dense flow part and a high powder snow component. The dense flow model is based on the granular model, in which the momentum is transferred by particle contacts and collisions. In the case of the powder part the mathematical model based on the fundamental principles of fluid dynamics and the effects of turbulence are taken into a two equation turbulence model. The two-dimensional granular flow model for the dense part and the three-dimensional turbulent powder part model are coupled by a simple transition model. The model allows to assess protective constructions such as avalanche dams or retaining walls as these enter the calculation by modifying boundary (terrain model) of initial (release zone) conditions. Upper limits of pressures on constructions can be obtained by considering dynamic avalanche pressure predicated by modelling. The verification of results of avalanche simulation is an important goal in the frame of research at the institute for Avlanche and Torrent research in Innsbruck. Further research is strongly demanded for finding of currect input data for the release area (e.g. snow depth, density), criteria which may influences enormously the result of the simulation.