AVAL-1D

Avalanche hazard maps are prepared by engineers and land-planners. These experts rely both on practical experience and calculation models to predict avalanche runout distances and flow velocities. Flowing and powder snow avalanche models have been under development for some time at the SLF. Emphasis was put on an easy-to-use graphical user interface for both flowing and powder snow avalanches. These one-dimensional computer-based models have now reached a level of development where they can be introduced to practitioners. The graphical user interface was programmed in IDL (Interactive Data Language).

Interactive dialogues enable the user to enter the parameters for avalanche (Xi, Mu, release conditions) and calculation (element size, time step, end time) and edit these parameters at any time. A dense-flow or powder avalanche can then be simulated. AVAL-1D contains two discrete calculation modules, namely FL-1D for dense-flow avalanches and SL-1D for powder avalanches, both of which were programmed in C. Both modules apply the finite difference method to solve differential equations describing the conservation of mass, energy and momentum.