Water Ecological Safety Assessment Of Three Gorges Reservoir Area Based On DPSIR Model

It is an important part of national security, the basis and carrier of other security as well as the country’s political security, financial security and military security. In the recent years, the domestic study of ecological security mainly focused on the evaluation of ecological security.Three Gorges section of Yangtze River have changed from the natural river to currently the world’s largest artificial lake, because of the construction of hydropower station. Since the impoundment of the Three Gorges reservoir got 156 meters, ecology and environment of Reservoir area have gone severe situation, as well the cyanobacteria bloom of tributary increasingly common. Therefore, the water ecological security assessment in the Three Gorges Reservoir area becomes a new point of view.In order to found out the water ecological security situation in the Three Gorges Reservoir area and served for the water environment management, we selected water ecological security index via DPSIR model, established evaluation index system of water ecological security on large reservoir, and analyzed the problems and causes on water ecological security of the reservoir area. Through collecting and standardizing the water ecological safety evaluation index data of Three Gorges Reservoir area, then analytic hierarchy process(AHP) and entropy weight method were used to establish assessment model, calculate ecological security index and evaluate the water ecological security of the reservoir area. The trends of water ecological security situation on the reservoir area were predicted by using GM(1,1) grey system.In this paper, we take Chongqing section and Hubei section of the Three Gorges Reservoir as research subjects, whose water ecological security were researched from the perspective of urbanization and agricultural pollution, respectively. The results shows that although ecological security situation of Chongqing section gets better year by year, the ecological security degree has always been in insecurity and warning state; the ecological security degree of Hubei section has tended to fall while in the warning state overall; the ecological security degree of Chongqing section will reach to grade I in 2018, while the degree of Chongqing section will be grade III. The water ecological security of Three Gorges Reservoir on Hubei section could be enhanced by increasing the urbanization rate and other measures.