用边际分析法确定黄河中游粗泥沙集中来源区

 为进一步寻找并治理对黄河下游主槽淤积危害最严重的粗泥沙集中来源区,根据1960年未建三门峡水库前自然水沙条件下下游河槽淤积物粒径组成,确定出黄河中游粗泥沙集中来源区界定中的粗泥沙界限为0.1mm。利用边际分析法在黄河中游多沙粗沙区确定粗泥沙集中来源区面积为1.88万km2。该面积仅占黄河中游多沙粗沙区面积的23.9%,可产生的全沙、粒径大于0.05mm和0.1 mm的泥沙分别占同期多沙粗沙区相应沙量的34.5%、47.6%和68.5%。由此看出,该区是名副其实的粗泥沙集中来源区。

Definition on source area of centralized coarse sediment in middle reaches of Yellow River with method of marginal analysis

In order to investigate and control the centralized coarse sediment source area where is the greatest damage to filling of main channel in the lower reaches of Yellow River, according to the size fraction of deposit in the main channel before 1960 in which Sanmenxia reservoir not be operated, that 0.1 mm is the limit of coarse sediment in the source area of centralized coarse sediment in middle reaches of Yellow River is concluded. Based on the method of marginal analysis, it is calculated that the centralized source area of coarse sediment is 18.8 thousand km^2, although the area is 23.9% of overloaded and coarse sediment region, the sediment discharge of total load, grain size larger than 0.05 mm and 0.1 mm is 34.5 %, 47.6 % and 68.5 % of the corresponding period of overloaded and coarse sediment region.