Quick-clay hazard mapping in Norway

Abstract

The Norwegian Water Resources and Energy Directorate (NVE) is responsible for the national quick-clay hazard mapping in Norway, and for the presentation of the quick-clay hazard zones that are identified. The first quick-clay hazard mapping started in the beginning of 1980, in the southeast and middle parts of Norway, initiated by the big quick-clay landslide in Rissa, Norway, in 1978. Today, there are nearly 2000 mapped quick-clay hazard zones in Norway, and the mapping is still ongoing. In the last years (2012–2015), the methods for evaluating quickclay hazard zones and the presentation of quick-clay areas have been developed through the multi-disciplinary research project Natural Hazards: Infrastructure for Floods and Slides (NIFS), which is a cooperation between the Norwegian National Rail Administration (NNRA), the Norwegian Public Roads Administration (NPRA) and the NVE. New and improved quick-clay hazard maps are one of the positive outcomes of this project. Increased accessibility to geotechnical data is important for the quick-clay mapping, which is improved through the new national database for ground investigations (NADAG). Another outcome of the NIFS project is the quick-clay areas mapped by the NPRA, which are shown together with the quickclay hazard zones on the NVE website. The NIFS project has also developed new methods for run-out areas and shoreline evaluation, which from now on will be included in the mapping.