位于长江中游的洞庭湖区为中国洪涝灾害频发地区之一。2010年的洪水是长江1998年大水后,也是三峡水库蓄水运用以来所遇到的首次较大洪水,在5次洪水过程中,三峡水库实施了5次防洪调度,较大程度地减轻了长江中下游地区的洪水压力。长江中游荆江既是连接三峡水库和长江中下游河道的纽带,又是沟通洞庭湖的水流通道。基于三峡水库出库流量与荆江三口、洞庭湖城陵矶的水文对应关系,以实测水情、灾情资料为依据,运用对比分析方法,揭示2010年汛期三峡水库防洪调度对减轻洞庭湖区的洪水压力及减少洪涝灾害损失的贡献率。结果表明:6～8月份三口入湖洪量减少约242.61×108 m3,湖口城陵矶洪水位降低0.82m;湖区减少洪涝灾害直接经济损失约19.983×108元,间接经济损失约0.638×108元。 The Dongting Lake region, located in the middle reaches of the Yangtze River, is one of the frequent flood-prone areas in China. The flood in 2010 was the first major flood since the flood in the Yangtze River in 1998 and also the impoundment of the Three Gorges Reservoir. During the five floods, the Three Gorges Reservoir implemented five flood control plans to a great extent Flood pressure in the middle and lower reaches of the Yangtze River. In the middle reaches of the Yangtze River, Jingjiang is not only a link connecting the Three Gorges Reservoir to the middle and lower reaches of the Yangtze River, but also a water channel for communication with Dongting Lake. Based on the hydrological correspondence between the discharge from the Three Gorges reservoir and the three rivers of Jingjiang and Chenglingji of Dongting Lake and based on the measured hydrological conditions and the data of the disaster, the flood control dispatching of the Three Gorges Reservoir in flood season of 2010 to alleviate the flood pressure in Dongting Lake area, Reduce the contribution rate of flood disaster losses. The results show that the flood volume of the three reservoirs decreased by 242.61 × 108 m3 from June to August, and the water level of Chenglingji Lake dropped by 0.82m. The direct economic loss of flood and water logging disaster in the lake area was about 19.983 × 108 yuan and the indirect economic loss was about 0.638 × 108 yuan .