Study On Vulnerability Evaluation And Zoning Of Geological Hazard In Reservoir Area Of Three Gorges Project

The Yangtze River Three Gorges Reservoir Area is one of the severest areas in geological hazard such as falling,landslide and debris flow throughout China. Disaster is a mixed result from risk of hazards and vulnerability of disaster bearers. At present, it is quite difficult to control sources and carriers of disasters. People may only protect disaster bearers and reduce their vulnerability in order to decrease loss from disasters. Then, reducing vulnerability has been a kind of important method for disaster mitigation. The aim for the paper is to make quantificational calculation of geological hazard vulnerability, and to make zoning and evaluation, and then to put forward disaster mitigation countermeasure for the Reservoir Area. Based on literature study, field investigate and specialist consultation, and make the Reservoir Area a research zone, and make its 20 popedoms evaluation zones. Know the Reservoir Area and analyze its vulnerability cause of formation from natural environment to social economy. Summarize the theory of vulnerability evaluation and fix on evaluation methods for the Reservoir Area. Then make pre-disaster and post-disaster evaluation with datas of social economic indexes and recent statistical disaster loss. In pre-disaster evaluation, adopt the method named fuzzy comprehensive evaluation and 6 indexes including population density, GDP density and so forth. In post-disaster evaluation, select the method based on post-disaster loss and 4 indexes such as disaster density, disaster frequency and so on. Complete vulnerability integrative evaluation and put forward disaster mitigation measures. The result is that the vulnerability degree of the geological hazard in the Reservoir Area is higher. There are 10 higher vulnerability zones including Yiling District, Badong County, Wuxi County, Wanzhou District, Kai County, Shizhu County, Yubei District, Banan District, Chongqing City Zone and Jiangjin City. There are 4 high vulnerability zones including Zigui County, Xingshan County, Wushan County and Changshou District. And there are 6 low vulnerability zones including Fengjie County, Yunyang County, Zhong County, Fengdou County, Fuling District and Wulong County. Higher vulnerability zones and high vulnerability zones should be emphasized in the future disaster mitigation plan. Larger differences exist in the evaluation zones because of different vulnerability factors. All the zones should adjust disaster mitigation measures to local conditions according to the vulnerability degree of local geological hazard. Furthermore, among the methods of prevention and mitigation of geological hazard, non-engineering measures e.g. adding disaster prevention investment, improving entironment and so on are primary, and engineering measures are subordinate.