Susceptibility assessment of shallow landslides triggered by rainfall in tropical basins and mountainous terrains

摘要

This study presents the analyses and results of the implementation of the SHALSTAB model to study landslides caused by rainfall that occurred on September 21, 1990, in a basin of tropical and mountainous terrain in the Colombian Andes. In 3 h, 208 mm of precipitation fell within the study area, triggering more than 800 landslides. This event is unusual because of the huge number of landslides that took place. The results obtained by the model are compared to an inventory of landslides that occurred during the event, which shows a high overlap in spatial locations. Additionally, a receiver operating characteristics analysis shows that SHALSTAB is able to capture the physics involved in landslides triggered by rainfall in tropical and mountainous terrains; this suggests that the proposed model could be implemented successfully in a variety of similar tropical regions to identify slopes prone to failure due to rainfall with only a high-resolution digital elevation model and a few soil parameters .