A new landslide database for Iceland: what it tells us.

Landslides pose a considerable risk over communities and infrastructure in Iceland. There have been large landslides in the recent years and a least one related to permafrost. Taking into account the changing climate, knowing past and active moving slopes increases preparedness for civil protection purposes. In order to have a better overview of the actual hazard, we mapped and classified all landforms reminiscent of landslides into a database. The mapping was done using aerial orthophotos, digital elevation models (DEM), and satellite interferometry (InSAR) velocity map. To begin with, this allows to extract statistics about the spatial distribution and size of various type of landslides. The largest landslide features mapped covers over 10 km², the smallest below 100 m². The most common type of large landform can be classified as complex: a mix of slide and slow flow. As expected, most landslides are located where there is steep topography: the West Fjords, the Trollaskagi peninsula, and the East Fjords. However, the distribution of landslide landforms is extremely varied within these areas. Some valleys show numerous landslides while other none. To help figuring out this heterogeneity, this database is put into relation with other type of geographical information: digital elevation models, lithology, bedrock geology, volcanic systems, faults, hydrology, permafrost, ground deformation velocities, constructions and infrastructures.