A Biviscous Modified Bingham Model of Snow Avalanche Motion

Abstract

A modified Bingham numerical model is developed and tested for the simulation of the motion of snow avalanches. This two-dimensional, incompressible model takes the form of a two-viscosity system in which a large viscosity is employed in the low stress regions of the flow and a smaller viscosity is used in the high stress regions. The model involves three parameters: the two viscosities, and the value of the stress for the transition between the two flow regimes. A simple no-slip boundary condition is used at the interface between the flowing snow and the stationary snow surface. Model parameters are evaluated by simulating the motion of the leading edge of the flowing snow, velocity versus depth information, and debris distribution of small snow test experiments.