Strategic research of flood hazard mitigation of Dongting Lake on the background of Three Gorges Project construction

Ecological environmental problems in Dongting Lake area have become more and more protruding in recent years The fragile and deteriorated eco environment along with rapid economic growth at the expense of overuse and irrational exploitation of land resources, resulted in shrinkage of Dongting Lake area and drop of lake level,thus aggravatius serious flood threat In this paper the strategy of flood hazard mitigation of Dongting Lake is discussed on the background of the Three Gorges project construction Water and silt coming from rivers of Yangtze, Xiangjiang, Zishui, Yuanshui and Lishui are key factors leading to flood hazards of the lake area The authors put forward some proposals about improving the relationships between the rivers and the lake, between the lake and protective embankments in lakeside areas, and between storing floodwater and sluicing flood water, between scouring and depositing Comprehensive security of hydrologic environment of Dongting Lake area is a prerequisite for large scale economic development. Based on requirements for safety construction of Dongting Lake area, combining with Three Gorges Project, this paper explores the interaction of Dongting Lake and Yangtze River runoff, discusses some problems about coordinating relationship between Yangtze River floodwater and Dongting Lake floodwater, strengthening safe facilities construction of water detention basin of the lake area, as well as recovery and reconstruction of life line and production line We should take into considerration of overall situation while making plans according to the interests of both Hunan and Hubei provinces It is of importance to the utilization of the Three Gorges Project to cut down floodwater entering Dongting Lake and to the improvement of the lakeside area's environment On the basis of flood disaster risk analysis of the lake area, we must strengthen construction of water conservancy facilities and realize scientific management between the Three Gorges Project and Hunan province's reservoirs