Research On Ecosystem Health Evaluation Of The Water-Level-Fluctuating Zone In The Three Gorges Reservoir-A Case Study Of Kaixian, Chongqing

The three gorges project is the largest water control project all around the world for the time being. After the impoundment of the reservoir 175m in normal operation, there will be 30-meter fall down belt between 175-meter normal impoundment and 145-meter flood control water level. Alternating controlled by aquatic and terrestrial ecosystems, and the reservoir distinction belt Strengthening the ecological protection with extinction falls away and frequent and intense material-energy exchange, the three gorges reservoir contains special and unstable ecosystem,which is also very sensitive to external changes and ecological fragile. Strengthen the protection of ecosystem and maintain the health of ecosystem of distinction belt were the foundation of playing its effectiveness of the three gorges project, and also the necessary condition of sustainable development.Based on the PSR conceptual model, the paper establishes the evaluation index system of ecosystem health of the extinction landscape scale. With the land use data of 2004 and 2009, the paper obtains each index information data of ecological health evaluation by means of remote sensing and GIS technology. It carries out ecological health evaluation of ecosystems with different elevations and ecosystem of distinction belt in Kaixian County, and simulation of distinction landscape after the completion of the project as well as warning of ecosystem health of distinction belt. Conclusions:(1) The terms of spatial changes:the health of low-elevation areas is relatively better than the high altitude; the more to the high altitude areas, the poorer health status.(2) The terms of the time changes:the ecosystem health of 2009 has improved over that of 2004, not only in each location on the elevation, but also in the fluctuating zone ecosystems.(3) It simulates the ecosystem landscape pattern after the completion of the project, and calculates that the reservoir ecosystem of Kaixian is in sub-health state.(4) Through the health warning analyses of distinction belt ecosystem, the paper arrives at the conclusion that there aren't worsening speed warning and negative evolution trend warning, indicating that the repository library will be beneficial for healthy development of distinction belt ecosystem.