Impact of Danjiangkou Reservoir on Sediment Regime of Hanjiang River

With the Baihe,Huangzhuang and Xiantao hydrological stations as the study objectives for researching of the impact of human activities on the sediment regime of the Hanjiang River,the study period was divided into two subperiods by the time when the gates of Danjiangkou reservoir was initially closed for water storage.The variations of annual,monthly sediment load,the sediment load of wet season and dry season,and the relation between runoff and sediment of the Hanjiang River were comparatively analyzed according to the observed data of daily discharge and sediment during 1955 to 2006.The result shows that the operation of Danjiangkou reservoir have significant influences on annual sediment load,the sediment load of wet season and dry season,the relation between runoff and sediment,and the monthly distribution of sediment load downstream.