Analysis of Density Current Flush in Xiaolangdi Reservoir During 2010 Pre-Flood Water and Sediment Regulation

Based on the observed date,from the aspects of flood process,boundary conditions,reservoir operation and so on,this paper studies the reason of high flush ratio of density current in Xiaolangdi Reservoir during pre-flood water and sediment regulation in 2010.Firstly,Sanmenxia Reservoir has large water storage,and therefore,it can model a flood process with large discharge and long duration.Secondly,when discharge released from Sanmenxia Reservoir began to increase,the water level of Xiaolangdi Reservoir approached delta peak,which caused a large quantity of streamwise erosion and headward erosion in delta top slope.Thirdly,when Sanmenxia Reservoir was in emptying period,there was a bigger discharge and a longer duration happened in Tongguan cross section.