Assessment of parameters for avalanche modelling by means of laser scanning and aerial photos.

Avalanches constitute a constant threat to Alpine areas. Simulation models assist in delineating hazard zones and optimising avalanche control systems. Digital terrain models serve as a basis for the simulation of avalanches and are especially suitable for modelling the dense flowing component. The powder component of an avalanche is influenced not only by the terrain but also by the condition and composition of the vegetation in the avalanche path. Remote sensing basically provides an effective tool for determining the input parameters required for avalanche simulation on a large-scale basis. This paper presents methods designed to precisely derive these terrain and vegetation parameters from laser scanner data and digital orthophotos. The methods have been developed under a project financed by the Austrian Federal Ministry for Agriculture, Forestry, Environment and Water Management and are planned for operational use in avalanche simulation and in assessing the protective capability of protection forests in the future.