Publication
Landslide hazard mapping aims at providing very useful information for urban planning and for risk analysis. Though landslide risks represent a common threat to human lives and properties worldwide, the procedures applied for hazard and risk assessment are far from being standardised, due to the diverse approaches adopted in each country. In this paper, two rock fall hazard mapping methodologies are compared, developed according to the French and Swiss guidelines respectively. The first was introduced based on the Guide for Natural Risk Prevention Plans (PPRN) in France, and is used by a bureau in the Rhone-Alps Region; the second was proposed according to the Swiss Recommendations, and is currently applied in the Canton of Valais in Switzerland. At first, the fundamental principles adopted in the two countries to take into account the rock fall hazards in land-use planning are presented. Then, after a brief description of each mapping method, a comparison of the corresponding hazard zonings is performed on a study site in the Canton of Valais. The obtained results are analysed along a 2-D slope profile of the selected site. They show that differences in hazard analysis philosophies, and/or in the mapping methods, may lead to very different zoning results and land-use restrictions.