Study on Operational Modes of Ice Flood Control and Flood Control at Inner Mongolia Section of the Yellow River

The paper studies the demands for ice flood control and flood control of Inner Mongolia section of the Yellow River based on the analysis of characteristics of ice flood and variation laws of silt-discharge condition of the section before and after the operation of Longyangxia and Liujiaxia reservoirs.The outcomes show that a) on ice flood control aspect,the channel discharge in freezing period should maintain 650-700 m3/s.The discharge decreases gradually in steady freezing period.The discharge in break-up period should maintain 450-500 m3/s and the storage capacity for ice flood control 831-1 104 million m3/s and;b) on flood control aspect,the controlled indexes for regulated discharge regime of the section should be discharge about 2 500 m3/s,duration about 12 days and water demand 2.5 billion m3.Deducting the mean channel discharge during the regulated discharge regime and considering the diversion of local area and incoming flow of tributaries,it needs to make up water 1.95 billion m3 for achieving the index of regulated discharge regime of the section.