Assessment of Rainfall-Induced Landslide Susceptibility Using GIS-Based Slope Unit Approach.

In this study, in order to map storm event-induced landslide susceptibility for central Taiwan, remote-sensing data were used to interpret landslides using a geographical information system (GIS). Discriminant analysis was used to establish rules that can successfully classify landslide and nonlandslide slopes. GIS-based slope units were used as the terrain subdivision to determine landslide susceptibility. A set of causative factors and a triggering factor were used to build a landslide prediction model. Data for shallow landslides triggered by three crucial rainfall events in July 2001, July 2004, and June 2006 were selected for developing the model. Among the factors used, the total accumulated rainfall is found to be a key factor in the interpretation of landslides. The landslide susceptibility maps were built for the Guoshin region and validated using predicting samples and data from a subsequent storm event, the 2008 Sinlaku typhoon. Results show that the developed model is capable of predicting the shallow landslide distribution induced by heavy rainfall in the study area. [ABSTRACT FROM AUTHOR]