三峡水库蓄水后长江中游干流来水量变化分析

Preliminary analysis on runoff variation of middle Yangtze River after impoundment of Three Gorges Reservoir

为了解三峡水库建成运用后对长江中游径流产生的影响,依据宜昌、汉口、仙桃、城陵矶等主要水文站多年流量资料,对三峡水库蓄水前后汉口站年径流量、径流量年内分配、年最小流量等进行了统计分析。结果表明,三峡水库蓄水运用以后,汉口站年径流量没有发生明显变化,但汛后流量减小、枯期流量增大,汛期则受三峡水库削峰拦洪影响,7,8月流量减小,径流年内分配也发生了一定变化。三峡水库蓄水运用对汉口站径流带来的变化有利于长江中下游的防洪与水资源利用。

The completion of Three Gorges Project will inevitably affect the runoff of the mid - lower Yangtze River. By analyzing the discharge data of Yichang, Hankou, Xiantao and Chenglinji hydrological stations along the middle Yangtze River, we study the annual runoff, inter - year distribution of runoff and annual minimum discharge of Hankou Station before and after im- poundment of Three Gorges Reservoir. The analysis results show that after the reservoir is completed and put into operation, the variation of annual runoff varies little, but monthly average discharge after flood season reduces while the monthly average dis- charge in dry season increases; in flood season, influenced by flood control of Three Gorges Project, the discharge in July and August decreases, the inter - year distribution changes as well. The operation of Three Gorges Project obviously improves the flood control and water resources utilization in the mid - lower reaches of the Yangtze River.