Abstract
This study analyzes the landslide event at Hsiaolin Village during Typhoon Morakot in 2009. This landslide event resulted in 400 deaths. This event indicates that extreme rainfall conditions can alter the disaster mechanism of a landslide. The extremely high intensity and cumulative rainfall events may cause large-scale and complex landslide disasters. To study and understand the landslide event a combination of field investigations and numerical models are used. The landslide area is determined by comparing topographic information from before and after the event. Physiographic parameters are determined from field investigations. These parameters are applied to a numerical model to simulate the landslide process.
And the landslide process was considered as two scenarios, a single event or a double event. For the single event, the main erosion area was the initial condition of the landslide movement. In Scenario II, the landslide process was divided into two parts. Finally, the simulation results were compared with investigation data. It shows the time of landslide movement is about 100 seconds. The deposited volume was well simulated. The deposited sediment formed a natural dam in the main channel. The minimum height of the dam is about 30 ~ 35 meter. The length of the dam is 1,100~1,600 meter.
