No abstract

Debris flows are complex fluid movements, in which water-laden masses of soil and fragmented rock rush down mountainsides, funneled into stream channels. The occurrence of debris flows in the Wudongde Dam site threatens human lives and structures. Hazard assessment of debris flow is important for natural disaster prevention and reduction. In this paper, 3S (Geographic Information System, Global Positioning System, and Remote Sensing) technologies were applied to determine the characteristics of debris flows. Nine factors of influence were acquired through 3S technologies. The catastrophe progression method was used to conduct hazard assessments of 27 debris flow catchments. The results show that the hazard levels for one of the debris flow catchments was high, twelve were moderate, three were low, and eleven were very low. The quantitative assessments made, based on nonlinear methods, are consistent with field investigations.