Preliminary Analysis of Water-Sediment Regulation Effect at Initial Stage of Sediment Retaining Operation for Xiaolangdi Reservoir

Xiaolangdi Reservoir is located at the critical section of the Yellow River to control the flow and sediment.According to the observation data from 1999 to 2008,water-sediment regulation effect at initial stage of sediment retaining operation for Xiaolangdi reservoir is analyzed.The results show that the released flow and sediment combination is improved distinctively;most of medium and coarse sized sands are retained in the reservoir and the released sediment is relatively fine;Under the conditions that both the inflow and sediment magnificently reduce,the process of sedimentation in the reservoir is slower than that as expected;the downstream of Yellow River is scoured continuously,which mainly concentrates on the upstream section of Gaocun;meanwhile the scouring strength is shown the trend of weakening along the river channel;the riverbed material in the downstream main channel becomes coarser obviously.;the section configurations are tended to be shallower and deeper;the shallow beach discharge is regained gradually;the flood and sediment releasing capacity of main channel is enhanced remarkably;the effect of continuous sedimentation reduction in Xiaolangdi reservoir and lower reaches of river channel is good.