Landslide risk management in Switzerland

Six percent of Switzerland is prone to slope instability. New federal regulations require regional authorities (cantons) to generate natural hazard maps and the zoning of mass movements in order to restrict development on hazard-prone land. The Codes of Practice for hazard maps use red, blue and yellow respectively, to indicate areas of prohibited construction, construction with safety requirements and construction without restriction. They need considerable efforts to ensure communication with local populations. The present state of landslide hazard mapping in the 26 cantons, the transcription of hazard maps to local management plans and the corresponding rules are presented.