Analysis on water level-discharge relation of Jingjiang River during low water level period before and after impoundment of Three Gorges Reservoir

After impoundment of Three Gorges Reservoir,the sediment silting in the reservoir and clear water discharge significantly impact the downstream rive channel.Through comparison of multi-year hydrological data of Jingjiang River channel before and after impoundment of Three Gorges Reservoir,the variation of cross-sections and water level-discharge relations of the main hydrological stations(Yichang,Zhicheng,Shashi and Jianli) on Jingjiang River during low level period are analyzed.The analysis results show that under the influence of clear water discharge of Three Gorges Reservoir,the cross-sections of Zhicheng and Shashi stations incised greatly and water level-discharge relations are lowered,so the water level is lowered during low level period at the corresponding discharge;the cross-section of Yichang station is basically stable and influenced less by Three Gorges Reservoir because of the influence of Gezhouba Hydropower project constructed before Three Gorges Reservoir.