Abstract:

Zigui County with prominent landslide hazard in Three Gorges Reservoir was taken as study area to conduct systematic research on landslide risk assessment. Based on the detailed analysis on landslide environmental factors, triggering factors, landslide inventory and the information of disaster bearing elements, landslide hazard was quantitatively assessed by using logistic regression model combined with statistical analysis method. The vulnerability of the population, buildings, lifeline engineering and land resources were calculated according to the landslide hazard intensity and the resistance ability of disaster bearing elements. Values attributed to disaster bearing elements were obtained by cost-value method for each element. Finally, landslide risk analysis considering life and economic costs were carried out through quantitative risk models in the studied area for next ten years. Highly risk areas of life and economic account for 1.11% and 2.71% respectively of the total studied area, and mainly distributed in the market town, school and enterprise residential quarters, transportation and construction land where there were dense population and prosperous economic value. Areas with moderate risk account for 13.21% and 20.66% separately, which were primary distributed in the rural residents and cultivated land. Low risk areas account for 85.68% and 76.63% individually mainly distributed in the area of treated geological hazard zone and little human activity of unutilized land and forest land. Combining with the field survey data, the risk analysis results were basically consistent with the status of local landslide disasters. It can be concluded that the critical areas, such as town, schools, enterprises, transport lines and so on, where damages are likely to be great require priority for mitigation actions.

Key words: landslides, hazards, vulnerability, risk assessment, Three Gorges Reservoir