Spatial and temporal variations of Norwegian geohazards in a changing climate, the GeoExtreme Project

Various types of slope processes, mainly land- slides and avalanches (snow, rock, clay and debris) pose to- gether with floods the main geohazards in Norway. Land- slides and avalanches have caused more than 2000 casual- ties and considerable damage to infrastructure over the last 150 years. The interdisciplinary research project "GeoEx- treme" focuses on investigating the coupling between me- teorological factors and landslides and avalanches, extrapo- lating this into the near future with a changing climate and estimating the socioeconomic implications. The main ob- jective of the project is to predict future geohazard changes in a changing climate. A database consisting of more than 20 000 recorded historical events have been coupled with a meteorological database to assess the predictability of land- slides and avalanches caused by meteorological conditions. Present day climate and near future climate scenarios are modelled with a global climate model on a stretched grid, focusing on extreme weather events in Norway. The effects of climate change on landslides and avalanche activity are studied in four selected areas covering the most important cli- matic regions in Norway. The statistical analysis of historical landslide and avalanche events versus weather observations shows strong regional differences in the country. Avalanches show the best correlation with weather events while land- slides and rockfalls are less correlated. The new climate modelling approach applying spectral nudging to achieve a regional downscaling for Norway proves to reproduce ex- treme events of precipitation much better than conventional