洞庭湖演变趋势分析

AN ANALYSIS ON EVOLUTIONAL TENDENCY OF DONGTING LAKE

洞庭湖的演变制约湖区的资源开发与环境整治。根据洞庭湖的湖底淤积与湖泊水面缩小的速率，分别论述了目平湖、南洞庭湖和东洞庭湖的自然演变趋势。结合三峡工程对洞庭湖的影响，分析了建坝后洞庭湖湖泊水面的变化及河流入湖三角洲的发育。

Dongting Lake,situated at the south of middle reaches of Yangtze River,is the secondlargest fresh water lake in China. If Dongting Lake evolves in the wake of natural course,itwould become a swamp,with several small lakes and channels in the next century accordingto the rate of the elevation of its bottom level and diminution of its surface.However,theThree-Gorge project of Yangtze River will have great impacts on the evolution of DongtingLake. On the one hand,water volume of Dongting Lake will reduce by 30～40 percent inOctorber;on the other hand.silt deposition will decrease and the rate of surface areareduction will be lower than at present after the construction of the Three-Gorge project.