This study established a hillslope failure susceptibility model for sediment disasters by combining the soil water index (SWI) and landslide susceptibility values to formulate a basis for warning release. The sum of the
rainfall depth in the three tank of tank model can be considered as the rainfall retention depth in soil layer. This study collected data of disaster cases and used them to establish lines of disaster coverage. The results indicated that the SWI alert value corresponded to the line of disaster coverage and the hydrological risk was related to disaster coverage.Furthermore, a landslide susceptibility model was constructed involving the frequency ratio method, which is based on landslide factors. The physiographic hazard level was obtained and normalized according to the landslide susceptibility
value. This study established a hillslope failure susceptibility model for sediment disasters by combining hydrological risk and frequency ratio based physiographic hazard levels.
Key Words: Tank model, Soil water index, Landslide susceptibility analysis, Frequency ratio method, Hillslope
failure susceptibility value.