三峡水库运用对荆江河道及三口分流影响研究

Impacts of Three Georges Reservoir's operation on Jingjiang River and outflow of the three outlets

三口河道是分流荆江水沙入洞庭湖的通道,自20世纪50年代,受自然条件改变及人类活动的影响,三口河道不断衰退。三峡水库运用后,拦截了大部分上游来沙,改变了长江中下游水文泥沙情势,三口河道进入新的调整周期。本文基于水文泥沙实测资料,分析三峡水库运用后荆江和三口河道冲淤及分流变化规律。研究结果表明,三峡水库蓄水以来,由于三口河道与荆江河道均发生冲刷,三口分流能力尚未发生明显改变,近年长江径流量减小及流量过程的改变是三口分流分沙量减少的主要原因。

Three tributaries of the Jinjiang River are pass ways of water and sediment diversion into the Dongting Lake. Since the1950 s,these tributaries have been in recession affected by natural conditions change and human activities. Three Gorges Reservoir intercepted most of the sediment from upstream,changed the situation of hydrology and sediment in the middle and lower reaches of the Yangtze River,the three tributaries enter the new adjustment cycle. In this paper,based on the measured data of hydrology and sediment,the evolution of erosion and deposition of the Jingjiang River and its three tributaries,as well as outflow were analyzed after the Three Gorges Reservoir operation. The research results have shown that diversion capacity has not been obvious change owing to the channel erosion occurring in the Jingjiang River and its three tributaries. The Yangtze River runoff decreased and the flow process changed is the main reason for reducing the number of water into the Dongting Lake.