Recent studies of regional landslide susceptibilities have been approached through multivariate statistics, taking only natural causes into account (viz. terrain, geology or hydrology variants). They offer, however,limited predictive accuracy for predicting rare events in urban areas and the effects of man-made construction. Thus,this study establishes a new susceptibility mode, taking into consideration the effects of construction (including density
of structures, density of roads, and disadvantageous index of man-made structures). The rainfall of Typhoon Nari,
a well known extreme rainfall event in Taipei city, was used as the triggering factor in the susceptibility model. The
results show that the accuracy reached 76.9% for both scenarios with natural causes and the effects of construction.Among these factors, the most crucial role was played by the disadvantageous index of man-made structures in the model. This study also suggests a set of thresholds for susceptibility classification and verifies its suitability when applied to other typhoon events after 2000.
Key Words : Buffer strips, SWMM, Vollenweider model, Nonpoint Source Pollution.