Debris flows are among the most dangerous processes in mountainous
areas due to their rapid rate of movement and long runout zone. Sudden
and rather unexpected impacts produce not only damages to buildings
and infrastructure but also threaten human lives. Medium- to regional-scale
susceptibility analyses allow the identification of the most endangered
areas and suggest where further detailed studies have to be carried
out. Since data availability for larger regions is mostly the key
limiting factor, empirical models with low data requirements are
suitable for first overviews. In this study a susceptibility analysis
was carried out for the Barcelonnette Basin, situated in the southern
French Alps. By means of a methodology based on empirical rules for
source identification and the empirical angle of reach concept for
the 2-D runout computation, a worst-case scenario was first modelled.
In a second step, scenarios for high, medium and low frequency events
were developed. A comparison with the footprints of a few mapped
events indicates reasonable results but suggests a high dependency
on the quality of the digital elevation model. This fact emphasises
the need for a careful interpretation of the results while remaining
conscious of the inherent assumptions of the model used and quality
of the input data.