1960年前黄河下游河槽淤积物粒径组成分析

Analysis on grain size composition of sedimentation materials in the Lower Yellow River before 1960

利用1999年汛前深层钻孔取样资料和历年淤积实测大断面资料分析出1960年前无三门峡水库影响的“自然”水沙情况下,下游河道主槽淤积物中d≥0.1 mm以上泥沙占50.7%,比1960-1999年大30个百分点,这种泥沙在下游的淤积比高达83.1%,比0.05 mm以上泥沙的淤积比高39个百分点。指出应在黄河中游寻找出0.1 mm以上的粗泥沙集中来源区作为近期水土保持的重点区域。

By using the deep-layer drilling samples before flood season of 1999 and measured sedimentation data in past years, the grain size composition of sedimentation materials in the main channel of the natural-state lower Yellow River without Sanmenxia reservoir before 1960 was analyzed. The result shows that the percentage of sediment size greater than 0. 1mm in the sedimentation was 50.7% before 1960, 30% bigger than that after 1960. Also, before 1960 the deposition ratio of sediments greater than 0.1mm reached 83.1%, 39% higher than the deposition ratio of sediments greater than 0.05mm. This knowledge may be helpful for one to find the area with large quantity of sediments greater than 0.1 mm as the key area to conduct soil and water conservation.