Debris flows and related landslide processes occur in many regions
all over Norway and pose a significant hazard to inhabited areas.
Within the framework of the development of a national debris flows
susceptibility map, we are working on a modeling approach suitable
for Norway with a nationwide coverage. The discrimination of source
areas is based on an index approach, which includes topographic parameters
and hydrological settings. For the runout modeling, we use the Flow-R
model (IGAR, University of Lausanne), which is based on combined
probabilistic and energetic algorithms for the assessment of the
spreading of the flow and maximum runout distances. First results
for different test areas have shown that runout distances can be
modeled reliably. For the selection of source areas, however, additional
factors have to be considered, such as the lithological and quaternary
geological setting, in order to accommodate the strong variation
in debris flow activity in the different geological, geomorphological
and climate regions of Norway.