采用原型资料分析、长河段一维数学模型计算等手段,分析和预测了三峡工程运用对洞庭湖水沙与冲淤影响,研究了三峡工程运用对洞庭湖出口水位的影响,在此基础上初步分析了三峡工程运用对湖区防洪与生态环境影响。研究成果表明:三峡水库运用后30a末,荆江三口年均分流量和分沙量比多年平均值分别减少43%和73%,三口分流道的河床相应发生冲淤变化;三峡工程运用后,受荆江三口分流比减少影响,洞庭湖区泥沙淤积显著减少,对增强洞庭湖区调蓄功能、延长洞庭湖寿命有利;受三峡水库调度运用与长江干流河道冲刷影响,洞庭湖出口水位以下降为主,汛期水位的下降将对湖区防洪有利,而枯期水位的下降将对湖区水资源利用及生态环境带来一定不利影响。 This paper analyzes and predicts the effect of the Three Gorges Project on the water and sediment and scouring and silting in Dongting Lake by means of the analysis of prototype data and the calculation of one-dimensional mathematical model of the Changjiang River. The impact of the Three Gorges Project on the water level at exit of Dongting Lake is studied. Based on this, Impact of Three Gorges Project on Flood Prevention and Ecological Environment in Lake Area. The results show that the annual average distributary and sediment flux of the three Jingjiang rivers decreased by 43% and 73% respectively over the mean of 30 years after the Three Gorges Reservoir was put into operation, with corresponding changes of scouring and silting in the three distributary channels. After the Three Gorges Project was put into operation, Jingjiang three diversion ratio to reduce the impact of sediment deposition in the Dongting Lake significantly reduced, to enhance the Dongting Lake storage and management functions to extend the life of Dongting Lake favorable; by the Three Gorges reservoir operation and the Yangtze River erosion, the Dongting Lake exit level to the main drop, The decrease of water level in flood season will be beneficial to the flood control in the lake area, and the decrease of water level in the dry season will bring unfavorable influence on the utilization of water resources and the ecological environment in the lake area.