Landslides and land-use planning in Switzerland: Codes of practice

More than 8 % of the swiss territory have been affected by landslides, mainly in the Prealps and the Alps. Land-use planning and the resulting zoning laws are among the most effective tools for the prevention of disasters in areas prone io mass movements. The new federal legislations require the Cantons to establish hazard maps and zoning for mass movements in order to restrict development on endangered land. Areas highly exposed to landslides have to be mapped at regional or local scale, yielding the so-called map of phenomenon, An uniform legend has been developped. The codes of practice also include some practical criteria to establish hazard maps, based on intensity and return period of the events, The transposition of these maps for the purposes of land-use planning are proposed for planners and policy makers.