黄河下游输沙能力的表达——“黄河调水调沙的根据、效益和巨大潜力”之一

Expression of Sediment Transporting Capacity of the Lower Yellow River——"Basis, Benefits and Huge Potentialities of a Regulated Discharge Regime of the Yellow River"(Ⅰ)

黄河下游输沙能力的表达,即不同河型的输沙能力公式。从公式可以看出,输沙能力的大小,除与泥沙粗细有关外,主要决定于坡降和河相系数。挟沙能力沿程调整的方式是:黄河下游上段游荡型河段坡降大,主要靠河相系数大来抵消;而下段弯曲型河段坡降小,主要由河相系数减少来补偿。

The sediment transporting capacity of the lower Yellow River is expressed by a formula of sediment transporting capacity of differ- ent river types. It shows that the sediment transporting capacity not only is related to the particle size of sediment, but also mainly depends on the slope and coefficient of fluvial facies. The way of regulated sediment carrying capacity along the river is as follows: the slope of braided reach at the upper section of the lower Yellow River is greater and mainly offset by large coefficient of fluvial facies and; the slope of mean- dering reach at the lower section of the lower Yellow River is smaller and mainly made up by the reduction of coefficient of fluvial facies.