Study on Water Diversion Capacity in the Middle Route of the South-to-North Water Transfer Project in Ice Period

The ice cover in canal can increase wetted perimeter,reduce hydraulic radius and increase hydraulic resistance,which can diminish the water diversion capacity of canal.The water diversion capacity of canal in winter is very important to design and management.In this paper,the factors to determine the water diversion capacity of canal are put forward,based on rising of water level and progress of ice cover.Through the calculation of steady nonuniform flow with composite roughness coefficient,water diversion capacity during freeze-up period and ice-covered period is researched and water diversion capacity is put forward for part of the Middle Route of South-to-North Water Transfer Project in north of Yellow River in winter.The results are important for water diversion of the Middle Route of South-to-North Water Transfer Project in ice regime.