Morphometric and multispectral image analysis of debris flows for natural hazard assessment

A set of Landsat Thematic Mapper (TM) multispectral variables was derived and then analyzed through multiple regression techniques to explain the presence/absence of 157 debris flows mapped through the interpretation of aerial photography for a portion of Glacier National Park, Montana, U.S.A. Morphometric characteristics of the mapped debris flows were assessed through digital elevation models, distance measurements from key target features, and derived site‐suitability models calculated within a geographic information system (GIS). Principal components analysis was used to determine the set of morphometric variables that explained the greatest proportion of the variation in the position of the mapped debris flows. Population vulnerability was assessed by relating locations of Park facilities used by visitors to the debris flow hazard map derived through the compositing of morphometric variables contained in the GIS.