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通过实测年系列水沙资料分析,运用统计分析方法,按照非萎缩期(1950～1985年)和萎缩期(1986～1999年)两个时期,分别得到黄河下游河道的冲淤临界值。对于年沙量、>0.05mm年粗沙量、年均含沙量、年均粗泥沙含沙量、年均来沙系数而言,冲淤临界值均有不同程度减小。这意味着河道萎缩后,由于输沙功能减弱,在年沙量、>0.05mm年粗沙量、年均含沙量、年均粗沙含量、年均来沙系数处于比非萎缩期更低的水平时,下游河道就有可能出现淤积,从而使得控制河道淤积抬高变得更为困难,使河道防洪面临新的问题。
Through the analysis of annual runoff and sediment data in the series of years, the scouring and silting thresholds of the lower reaches of the Yellow River are obtained respectively according to two periods, ie non-shrunken period (1950-1985) and shrinkage period (1986-1999), using statistical analysis methods. For annual sediment volume> 0.05mm annual coarse sediment amount, average annual sediment concentration, mean annual sediment concentration, annual mean sediment yield, the critical values of scouring and silting decreases in varying degrees. This means that after the river channel atrophy, due to the weakened sediment transport function, in the annual sediment,> 0.05mm annual coarse sediment, average sediment concentration, average annual coarse sand content, the annual mean sediment yield is lower than non-atrophy The siltation of downstream rivers may occur, which makes it more difficult to control the siltation of the river and makes the flood control of rivers facing new problems.