Evolution récente des cartes d'avalanche en France

Since 1971, we use CLPA maps (past and geomorphic map of avalanche), as the main registration maps concerning the major threatened areas, especially the villages. Few years later (1984), in order to perform the land planning process in which we have to assess what the avalanche hazard level might be, appeared the first legal avalanche risk zoning maps (called PPR - Risk Prevention Plan). These two supports are not easily connected but significant progress in the methods appeared after 1999. This poster details the most recent evolutions of avalanche mapping methods: In the first part, the main evolutions of CLPA production process are described with a special focus put on the better coordination between forest rangers (in charge of a permanent avalanche survey) and avalanche mapping specialists. To improve this preventive action, an annual update distribution of digital files and via internet is set up now. The second part details the main expert assessments to be used in the PPR mapping process: from the determination of potential hazard (considering the return period and the power of avalanche) to the representation by zones of different land-use prescription. Corresponding to each zone, specific rules on housing and land planning process are applied.