Snow avalanche and rock slide - rough susceptibility zones
The susceptibility areas for snow avalanches and rockslides show susceptibility areas collectively for the two landslide types. The risk of snow avalanche is generally the design value for the extent of the susceptibility areas, as snow avalanches normally have the greatest range. The susceptibility areas in these maps are identified by using slope maps to identify terrain where landslides may be triggered. The runout areas are calculated using an empirically based model, developed by NGI. This work is done manually. After that the relevant areas are inspected and assessed by landslide experts before defining the boundaries of the susceptibility areas. This series of maps covers parts of the country. Only areas that can be reached from roads are inspected, and hence each map sheet includes large areas that have not been assessed. The extent of the susceptibility areas on these maps is normally less than the susceptibility areas in the nationwide, automatically generated susceptibility maps for snow avalanches, as acquiring the knowledge of landslides by means of inspections has also provided the opportunity to take into account local factors that reduce the landslide run-out area such as forests, terrain details and suchlike. The susceptibility areas do not include areas that may be susceptible to slush avalanches.
Submitter: Norwegian Mapping Authority
Owner: Norwegian Water Resources and Energy Directorate
Version number 1