Analyse spatiale, évaluation et cartographie du risque glissement de terrain

Spatial analysis and GIS technology are still seldom used to evaluate and map landslide risk. Especially, few studies concern the automatic mapping of landslide risk at large scales (1:10,000) corresponding to the scale of the legal regulation plans in France. Maquaire et al., Analyse spatiale du risque « glissement de terrain » 2 This paper presents a three-step procedure to map landslide risk in mountain areas. First, landslide susceptibility (e.g. the spatial component of the hazard) is evaluated with a bivariate probabilistic model. The model simulates the relationship between several environmental factors controlling landslide location and the observed past and present landslide distribution. Second, landslide potential consequences (damage) are evaluated through the identification of the elements at risk (or stakes) and their value with a semiempirical model. Finally, landslide risk is evaluated by combining the susceptibility maps and the consequence maps. The methodology has been developed within the EU-funded project ALARM (Assessment of Landslide Risk and Mitigation in Mountain Areas, 2001-2004) and has been applied in the Barcelonnette Basin (French South Alps). MOTS-CLÉS : glissement de terrain, risque, susceptibilité, analyse spatiale, modélisation, SIG