黄河粗泥沙界限与中游多沙粗沙区区域研究

本文首先讨论了黄河粗泥沙界限的确定方法，认为以下游淤积物中占多数的观点来确定黄河粗泥沙粒径界限较好，经分析淤积物中0．025mm以上的泥沙占多数，0．05mm以上的泥沙近半数；然后讨论了中游多沙粗沙区区域界定的两种方法，认为指标法能够直观反映出多沙粗沙区的位置I最后甩0．OSmm和0．025mm两种界限分析了多沙粗沙区面积，分别为8．15万km^2和6．99万km^2．两者位置和面积比较接近，但在治理方略上有一定差异．前者强调治沟治基岩，后者强调沟坡兼治。

Delimitation of coarse sediment and study on overlap of coarse sediment and sediment abundant areas in the middle Yellow River Basin

The delimitation of coarse sediment is stated in this paper. It is better to differ coarse sediment and fine sediment according to the predominant sediment deposited in the Lower Yellow River. Analysis shows that particles bigger than 0 025mm are prevailing and those bigger than 0 05mm are nearly 50%. Two methods to delimit the region for overlap of coarse sediment and sediment abundant areas in the middle Yellow River Basin are discussed. The index presentation method can explicitly reflect the location of overlap for coarse sediment and sediment abundant areas. The areas of the regions where the coarse sediment and sediment abundant areas overlap corresponding to the criteria of 0 05mm and 0 025mm are 81500km 2 and 69900km respectively. Although the areas for the two regions are not significantly different, but the treatment policies are different in some extent. The former emphasizes the treatment of gully and base rock and the latter encourages the treatment of the combination of gully and slope.