Susceptibility assessment of rainfall-triggered flows and slides in the central-eastern Pyrenees

摘要

Rainfall-induced flows and slides are hazardous processes in mountainous regions and susceptibility assessments with resulting maps are helpful tools for land-use planners. In the present study, all the available information on recent events has been gathered and incorporated in an inventory. The governing factors of the 2262 entries were analyzed and preliminary susceptibility matrices were established. Two different terrain units were applied and compared: grid cells and first-order catchments. The results showed that slope angle between 30 and 35º and land cover classes like debris screes or grassland are the most significant factors. In addition, the Melton Ratio higher than ∼0.7 in the first-order catchments seems to be another critical parameter. Finally, two types of susceptibility maps were created, although the ones working with first-order catchments look more appropriate for the application at regional scale and the use for land-use planning.