Models for powder snow avalanches : comparison of two approaches
Abstract
Two models are considered in this paper: one was proposed in Kulikovskiy and Sveshnikova (1977) and is referred here as KS-model, the second was described in Beghin and Brugnot (1983), and is referred here as BB-mode!. Both models treat the powder avalanche as a cloud of finite length and calculate the front velocity, the dimension and the mean density of the cloud. They are very similar as the geometry of the cloud is assumed to be an elliptic half-cylinder. The BB-model is included in a software presently used in France for design purposes. It contains some simplifying assumptions that are not needed in the KS-mode!. The aim of this paper is to study the validity of the BB-model simplifications by comparison of the two models. We first simulate the Beghin and others (1981) experiments in water by KS-model and then compare the two models' results in the case of a snow avalanche on a uniform slope. We find that an appropriate choice of the air entrainment coefficient value for the KS-model leads to reasonable similar results for the two models, in both cases for large ranges of slope and cloud density.