第一造床流量及输沙能力的理论分析——“黄河调水调沙的根据、效益与巨大潜力”之三

Theoretical Analysis on First Bed-Forming Discharge and Sediment Transporting Capacity

第一造床流量是代表变动流量过程输沙能力的等价流量,即塑造河道纵剖面的造床流量,其能从理论上确定。计算结果与实测资料对比表明,在输沙作用方面,它确实有很好的代表性,且利用它确定输沙量时可避免很多频繁的计算。黄河下游河道输沙特性及输沙能力结构分析表明,利用挟沙能力级配可较好地反映冲淤和平衡条件下的挟沙能力规律,在冲淤条件下挟沙能力具有非单值性。这些分析,揭示了黄河下游复杂输沙现象的结构及多来多排的机理。

The first bed-forming discharge represents equivalent discharge of sediment transporting capacity in variable discharge process,i.e.the formative discharge forming longitudinal section.It can be decided in theory.The outcomes of calculation and contrast of observed data show that it has good representativeness on sediment transport and can avoid frequent calculation in deciding sediment discharge.The analysis on the characteristic and capability structure of sediment transport of the lower Yellow River channel show that it can fairly reflect the rule of sediment carrying capacity under the conditions of scour,fill and equilibrium by using sediment carrying capacity gradation and the sediment carrying capacity possess non-uniqueness in scour and fill condition.The analysis delineates the structure of complicated sediment transport and the mechanism of discharge more as coming more of the lower Yellow River.