Variation trend of runoff and sediment load in Yangtze River

The variation trend of runoff and sediment load in Yangtze River was analyzed,based on 50 years hydrological data.It is found that,the yearly-averaged sediment load is obviously decreasing at Hankou,Datong and Yichang hydrological station,and the yearly-averaged sediment load is also decreasing at all tributaries in Yangtze River.Among them,the largest amount of reduction can be found at Huangzhuang on Hanjiang River,which is one of the biggest tribtutaries of Yangtze River.On the other hand,yearly-averaged sediment load is increasing in Jinshajiang,the upstream of Yangtze River.The reduction of flood and sediment diverted to Dongting Lake from Yangtze River result in the increase of sediment in the lower reaches of the River.According to the analysis the probable deposition and scour in the river reaches downstream of Yichang are forecasted which is important to the operation of the Three Gorges Project.