黄河下游河道输沙用水量研究

从上游来水来沙状态、下游河道输沙目标、下游河道水流输沙能力和水利枢纽调控调度4个层次分析了黄河下游河道输沙用水效率。根据1950－1997年期间的实测资料，分别讨论了黄河下游不同河段在自然、受控、复杂和异常状态下的输沙用水量。在各种状态下根据河道和输沙特性的差异，分别按照均衡和平衡输沙目标计算了下游河道输沙用水量。在设定输沙目标下，以年内不同时段水流挟沙能力为依据，对比了可能提高输沙用水效率的不同调控方案，例如在汛期或7－8月输送全年泥沙的方案等，以便减少黄河下游输沙用水量并缓解黄河水资源的紧张趋势。这些方案有可能通过水利工程枢纽的调控来实现，为此中给出了不同状态下均衡、平均输沙用水量可调控的阈值。

Water Demand for Sediment Transport in the Lower Yellow River

Water demand for transporting sediment is of primary importance in the Lower Yellow River. A systematic analysis was made in terms of the incoming water and se d iment from the upstream, the regimes of sediment transport, the sediment trans po rting capacities of river flow, and the control capabilities of hydraulic eng ine ering works. According to the measured data from 1950 to 1997, the water dem andfor transporting sediment was considered under four conditions, or the natu ral,the engineering-controlled, the complex and the abnormal conditions. Boththe e quilibrium and the non-equilibrium regimes are discussed. In determiningequili brium regime for sediment transport, comparison was made between differe nt opera tion schemes in connection with sediment transporting capacities, e.g.the schem e of using the water in wet season to transport the sediment load in t he whole y ear and other schemes. These schemes could decrease water demand forsediment tr ansport. The schemes could be implemented by the option of the hydra ulic enginee ring works. For convenience, thresholds of water use for sediment t ransport unde r different conditions were also proposed and discussed.