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根据高效输沙(冲刷)和防洪安全对主槽断面形态的要求、未来洪水的可能造床能力,提出黄河下游主槽的过流能力应不小于4000m3／s．主槽断面的塑造过程是洪水动力克服河床阻力做功的过程,洪水对主槽的塑造作用来自洪水造床动力与河床阻力之对比．对非漫滩的中低含沙洪水,主槽的塑造机理可简化为断面变化量与WαQβ的关系;就塑造一定断面的主槽而言,所需洪水动力W0.32Q0.37是一定的,若流量较大,则需要的洪量可减少;要使某场洪水具有冲刷主槽的作用,其洪水动力特征值W0.32Q0.37应大于41．并非所有漫滩洪水都具有淤滩刷槽作用,对中低含沙洪水,只要当洪水流量达平滩流量的1．5倍以上时,主槽才出现明显冲刷．
According to the requirements of high-efficiency sediment transport (sedimentation) and flood control on the profile of the main channel and the potential capacity of future flood, it is proposed that the over-current capacity of the main channel of the lower Yellow River should be not less than 4000m3 / s. The shaping process of the main channel section is the process by which flood power overcomes the resistance of the riverbed. The shaping effect of flood on the main channel comes from the contrast between the flood-forming power and the riverbed resistance. For non-floodplain medium-low sediment floods, the shaping mechanism of the main channel can be simplified as the relationship between the change of section and WαQβ. For the main channel of a certain section, the required flood power W0.32Q0.37 is certain, If the flow rate is larger, the flood volume needed can be reduced. For a flood to have the effect of scouring the main channel, its flood dynamic characteristic value W0.32Q0.37 should be greater than 41. Not all floodplain floods have the effect of silt brushing trough. For medium and low silt flood, as long as the floodwaters flow rate is more than 1.5 times of the flat beach flow, obvious flushing occurs in the main trough.