Spatio-temporal distribution of extreme weather events and natural hazards (snow avalanches and rockfalls) in Norway

Abstract

The InfraRisk project is concerned with the impacts of extreme weather events (EWE) on the Norwegian transport infrastructure. Natural hazards triggered by EWE's are thereby of central concern. Transport routes running through or along steep terrain are frequently affected by natural hazards, predominantly by snow avalanches, rock falls, and debris flows.

The trigger mechanisms of these processes are not fully understood yet. It is generally assumed that the release of snow avalanches and rock falls is related to certain (extreme) weather events. The relation between snow avalanches and precipitation during winter is, to a certain extent, straight forward. The relation between individual climatic variables and rock falls is less obvious and strongly influenced by other relevant factors such as continuous weathering, freeze-thaw events and geological preconditions.

The present note reports about the analysis of how the distribution of rock falls and snow avalanches (stored in the national slide database, skrednett.no) is related to the spatio-temporal distribution of precipitation events and freeze-thaw events (as registered at meteorological stations).