Debris-budget-based debris-flow susceptibility analysis

Abstract

Susceptibility analysis of debris-flow is important for mitigating the induced hazards. This research proposed a statistical model for predicting the occurrence of debris-flow in Tungshih, Taiwan. Five causative factors including steepness of creek, catchment area, form factors, potentially landslide area and debris storage index were selected in the statistical model. Based on the record of debris-flow occurrence during typhoon Toraji, the steepness of creek, potentially landslide area and debris storage index were sieved as relevant causative factors of the occurrence of debris-flow. By taking the debris budget into account, the susceptibility of debris-flow will evolve with the landslide and debris-outflow. Thereafter, the impact of geological events, such as a large earthquake, on the occurrence of debris-flow can be predicted and quantitatively evaluated. © 2008 Science Press Beijing and Springer-Verlag GmbH Berlin Heidelberg Geotechnical Engineering for Disaster Mitigation and Rehabilitation.