DEVELOPMENT OF A HAZARD MAPPING METHOD FOR DEBRIS FLOW IN DISASTER-PRONE AREAS

Abstract

Morphological and hydrological conditions are main factors to influence the probability and magnitude of sediment disasters. This study tried to develop a method for hazard mapping of sediment disasters from these two aspects. Aerial photographs and historical debris flow susceptibility analysis were used to distinguish the potential debris flow torrents, digital terrain model was used to make the topographic data, and hydrologic frequency analysis was used to evaluate the probable discharges extreme value from two survey stations in a study watershed in Taiwan. Finally, the results made in the first part were input in the Flo-2D software model to simulate the deposited area for each torrent. To create a hazard map, the results from simulation were divided into several levels in terms of danger based on landslide intensity.