faSavageHutterFOAM 1.0: depth-integrated simulation of dense snow avalanches on natural terrain with OpenFOAM

Numerical models for dense snow avalanches have become a central part in hazard zone mapping and mitigation. Several commercial and free applications, which are used on a regular basis, implement such models. In this study we present a tool based on the open-source toolkit OpenFOAM ® as an alternative to the established solutions. The proposed tool implements a depth-integrated shallow flow model in accordance to current practice. The solver combines advantages of the extensive OpenFOAM infrastructure with popular models from the avalanche community. OpenFOAM allows assembling of custom physical models with build-in primitives and implements the numerical solution at a high level. OpenFOAM supports an extendable solver structure, making the tool well-suited for future developments and rapid prototyping. We introduce the basic solver, implementing an incompressible, single-phase model for natural terrain, including entrainment. The respective workflow, consisting of meshing, pre-processing, numerical solution and post-processing, is presented. We demonstrate data transfer from and to a geographic information system (GIS), to allow a simple application in practice. The tool-chain is based entirely on open-source applications and libraries and can be easily customized and extended. Simulation results for a well documented avalanche event are presented and compared to previous numerical studies and historical data.