Blowing and drifting snow influences human activities in various ways. For example, in mountainous regions, snow drift is a key factor in the formation of slab avalanches; the quality of avalanche danger mapping and land-use planning depends significantly on the correct assessment of snow redistribution by drift in avalanche release zones.
A physically-based numerical model was developed to simulate snow drift in alpine terrain. The model is based on the separation of the involved processes into two layers. The upper layer describes the transport in suspension and the wind field. The wind field is modeled by the Reynolds averaged Navier-Stokes equations, using the e-ε (k-ε) model for turbulent closure. Suspended snow is modeled by an additional scalar equation. The bottom layer describes the transport due to saltation, including erosion and deposition of snow. Both layers are mutually coupled by boundary conditions.
As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements. To this end, an experimental site 2 km north from the SFISAR Institute building at Weissfluhjoch, Gaudergrat ridge (2300 m a.s.l.), was equipped with instruments to measure meteorological and snow parameters.
The comparison between field measurements in a complex alpine terrain and numerical simulations shows that the snow drift model is suitable to predict the new~snow distribution in extended areas.