Modeling waves and short-lived peak velocities and impact loads associated with snow avalanches

Abstract

The one-dimensional, unsteady, gradually varying free surface, open channel equations are solved numerically using the lax diffusive scheme. The numerical model is applied to simulate avalanche flow and to capture the existence of waveforms leading to the estimation of short-lived peak velocities and impact pressures for any point along a given avalanche track. The simulation of both laboratory and field experiments are presented to demonstrate the viability of the discretization scheme. To verify numerical results of this new numerical model, results from the Swiss hydraulic continuum model for avalanche motion are presented and compared. The lax diffusive scheme provides acceptable results when compared to these laboratory and full-scale avalanche results and when compared to the Swiss numerical results. Simulations are presented to demonstrate the ability for the numerical model to capture and track waveforms within the avalanche flow, to estimate short-lived peak velocities and impact pressures for any position along the avalanche track—especially when perturbations (i.e., terrain changes) are introduced into the flow. These perturbations are particularly evident when releasing a wave-like form from rest down an incline. Difficulties are encountered when trying to simulate in situ results and recreating the richness of the data.