黄河下游塑槽输沙需水量计算方法

Calculation methods of water demand for channel forming and sediment transport in the Lower Yellow River

本文从能量平衡原理出发分析了挟沙水流的能量耗散机理及水流塑槽和输沙能量的分配模式,河道水流能量的消耗主要用于塑槽和输沙两个方面,即一部分水流能量用来克服河床边界阻力,维持一定的河道主槽;另一部分则用于输送水流中挟带的泥沙,维持河道的输沙平衡。根据水流能量的这一分配模式,并结合水沙条件对平滩流量的累积影响作用,建立了塑槽输沙需水量的计算方法。将该方法用于黄河下游各主要测站的塑槽输沙需水量计算,取得了较好的效果。以三黑小的来水来沙为输入条件,得到了黄河下游河道塑槽输沙需水量的计算公式,并给出了维持黄河下游平滩流量为4000m3/s的塑槽输沙需水量区间。

The energy dissipation mechanism of sediment-laden flow and the energy allocation for both channel forming and sediment transport were studied based on the energy balance principle. It is believed that the energy consumption of river flow is utilized in two ways： channel forming and sediment transport. One part of the flow energy is used to overcome the resistance of channel boundary, and another part of the flow energy is used to transport the sediment carried by the flow, in order to maintain an equilibrium state in sediment transport. Methods for the calculation of water demand for channel forming and sediment transport in lhe Lower Yellow River were developed based on the energy balance principle and in combina- tion with the cumulative effect of flow discharge and sediment load on bankfull discharge. Satisfactory re- suits were obtained when the developed methods were applied to the calculation of water demand at major hydrological stations in the Lower Yellow River. Furthermore, a method for the calculation of water demand for the whole Lower Yellow River course was proposed by utilizing the water discharge and sediment load in the reaches of San-Hei-Xiao as the input variables. Formulations for the range of water demand for the maintenance of a bankfull discharge of 4 000m3/s in the Lower Yellow River were provided.