Study on the Response of Lake Chaohu Eutrophication to Yangtze River - Lake Chaohu Water Transfer Project

The eutrophication of Lake Chaohu is long-time integrated and the accumulative effect of pollution load, hydrological regime and exterior condition and so on are examined. One of the direct reasons leading to deterioration of the hydrological situation is the gate dams regulation. As the large-scale water transfer project of water resources allocation in Anhui Province in the new century, the Yangtze River-Lake Chaohu water transfer project is beneficial to accelerate water flow of the lake, enhance self-purification of the lake, extend water environmental capacity and alleviate eutrophication of the lake. Through establishing a BP network model of the Lake Chaohu eutrophication forecast, the response of Lake Chaohu eutrophication to Yangtze River-Lake Chaohu water transfer project is studied by means of numerical simulation. The results show that all of the four water transfer alternatives could alleviate the situation of Lake Chaohu eutrophication. In detail, TLI (trophic status index) of the west part sampling site will reduce to middle eutropher from hyper eutropher and TLI of the east part sampling site will reduce to mesotropher from light eutropher, that is to say both of the west and east part will reduce one grade of eutrophication level. Especially, by implementing project of Caizi Lake and Fenghuangjing joint water transfer, TLI of the west and east part will reduce most. The Lake Chaohu water transfer project is a good opportunity to control Lake Chaohu eutrophication. Additionally, large-scale water transfer is also a double-edged sword to the ecosystem along the route, and it is also necessary for us to realize drawbacks of implementation of the Yangtze River-Lake Chaohu water transfer project, such as short circuit of lake flow, stagnation of lakes due to lots of sediment from the Yangtze River and eco-risk of soil gleying along inlet rivers. Therefore, we should develop an optimal project design and take countermeasures to guarantee completion of the eco-aim of the project successfully.