Operation of Sanmenxia Reservoir on the Control of Flood and Ice Run after Xiaolangdi Project Operated

Joint operation of Xiaolangdi with Sanmenxia,Luhun and Guxian Reservoir,together with other works for flood prevention,will be instrumental to raising effectively the present standard of defending flood on the lower Yellow River, alleviating burden of Sanmenxia Reservoir in flood and ice run control and reducing deposition in the reservoir .When flood occurring mainly in the upstream of Sanmenxia,Xiaolangdi and Sanmenxia Reservoir will put into joint operation. There are three flood control methods for Sanmenxia Reservoir. These are respectively : (1) All outlets are opened free during flood peaks; (2) The reservoir is not adequate control until maximal storage level reaches; (3) The reservoir is not adequate control until certain storage level of Xiaolangdi Reservoir occurs .The research results show that the third flood control method is the best.