The Reseach Of Ecologival Copensation Technique For The Two Lakes From The Three Gorges Project

The Poyang Lake and the Dong Ting Lake, as two indispensible wetlands to China, has been changed as far as its eco-hydrologic process is concerned after the establishment of the Three Gorges Dam, which is going to affect the perching water area and habits of the important creatures of the two lakes, change their structures and distributions, and therefore, bring profound influences to the ecology and environment of the two lakes.The article, based on Item 4 of the Study on Ecological Safety-based Cascaded Water Resources and Hydropower Projects Compensation Technology of Program 8 of Joint-operating Technology for the Supergiant Cascaded Central Group at the Three Gorges and the Upper Reach of the Yangtze River (2008BAB29B08), which is under the program of Study on Several Key Technologies on Safe and Efficient Operation of Supergiant Cascaded Water Resources and Hydropower Projects sponsored by the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period, is dedicated to studying on the effect of the Three Gorges Project on the eco-hydrological process of the two lakes, identifying the ecological water-level control demand through hydro-ecological simulation based on the responding relationship between hydrological change and ecological environment, further confirming the water-level control demand of the mainstream of the Yangtze River through hydrodynamic model, and then proposing the technical terms on ecological compensation for the two lakes area.Based on the research background and contents of the article, and combining the research results at home and abroad, the article mainly covers the following aspects:(1)Establishing the two-dimensional hydrodynamic model for the two lakes area with MIKE21 for the first time. The model, with the inflow of the area as the upstream control boundary, and the water-level at the lake mouth as the downstream control boundary, is able to provide the results with acceptable difference and satisfactory accuracy through rating result analysis, and thus be a tool for water-level control identification of the mainstream of the Yangtze River.(2)Analyzing the ecological problems of the area, evaluating the influences of the Three Gorges Project on the eco-hydrological process, and proposing countermeasures for ecological environment recovery of the area.(3)Analyzing the minimum ecological water-level of the Dongting Lake through lake morphological analysis method, and the appropriate ecological water-level for white crane living in Poyang Lake in winter through hydro-habitat experience model based on habitat protection.(4)Identifying the water-level control demand of the mainstream of the Yangtze River through the simulation of two-dimensional hydrodynamic model, and then proposing the compensation terms for the two lakes area.