Flood control and shrinkage in the Haihe River Mouth

Abstract

Because of overusing water resources in the upper and middle reaches of the Haihe Basin, less and less water flows to the river mouth. The Haihe River flow is cut off in most time of the seasons, sediment deposited in the river mouth channel is rarely scoured away, and many of the river mouth channels have been shrinking quickly. The discharge capacity of the channel is consequently reduced greatly, which results in more and more serious flood hazard. Many tide gates have been built for storing fresh water and preventing the salty and turbid water. The channel downstream of the gate is silting up and people have to dredge the channel every year before the flood season. This paper studies the laws of the siltation and strategies controlling channel shrinkage. The strategies are digger dredging, trailer dredging, scouring with pumping water or storing tidal water, building double guiding dikes and building a new gate. Comparison of various strategies is performed, suggesting the most effective strategy controlling estuarine channel shrinkage.