Discussion on the Construction of Sediment Retention Works in the Concentrated Coarse Sediment Source Areas of the Yellow River

摘要

The sticking point for the regulation of the Yellow River lies in sediment,where coarse sediment is most critical.Ever since a long time ago,a large quantity of sediment moves to the lower Yellow River due to severe soil loss from the loess plateau,particularly the coarse sediment fraction which silted in the lower course,directly threatening the safety of the people and properties on both banks of the lower Yellow River.Trapping of the sediment to the Yellom River in the loess plateau region of the Yellow River Basin is the most effective solution to the Yellow River sediment problem.There are 454,000 km2areas subject to soil erosion in the loess plateau region of the Yellow River Basin,which mean a very high difficulty in harnessing,and that long-term unremitting efforts are needed.In order to make the limited investments give play to the effect of sedimentation reduction as early as possible,the coarse sediment that make the biggest contribution to the sedimentation of the lower Yellow River must be controlled.Years of research shows that the 18,800 km2 concentrated coarse sediment source areas of the middle Yellow River are the key to stopping the coarse sediment from flowing into the Yellow River.Construction of sediment retention works in these areas can play an enormous role in balancing runoff-sediment relationship,containing the uninterrupted development of course shrinking and "secondary suspended river",reducing the sedimentation of the lower course,and extending the service life of the large reservoirs for sediment retention.This paper analyzes the influence of the coarse sediment on the rise of the lower riverbed,discusses the construction measures,layout and scale of the sediment retention works,predicts the effect of construction of the sediment retention works in the concentrated coarse sediment source areas,and addresses the safety issues to which attention must be given in the engineering construction.