低含沙量条件下黄河下游水流挟沙力公式及其应用  

Determination of Parameters in the Formula for Sediment Transport Capacity in Low Sediment-laden Flows and Its Application in the Lower Yellow River

作　　者：程亦菲 夏军强[1] 周美蓉[1] 鲁俊 CHENG Yifei;XIA Junqiang;ZHOU Meirong;LU Jun(State Key Laboratory of Water Resources Engineering and management,Wuhan University,Wuhan 430072,China;Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003,China)

机构地区：[1]武汉大学,水资源工程与调度全国重点实验室,湖北武汉430072 [2]黄河勘测规划设计研究院有限公司,河南郑州450003

出　　处：《应用基础与工程科学学报》2024年第4期1011-1023,共13页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(U2243238,U2243237,51725902)。

摘　　要：水流挟沙力公式及其参数的选择,对泥沙输移过程计算有重要影响.小浪底水库运行后,黄河下游发生低含沙量洪水的频率增大,因此挟沙力计算关系的适应性需要重新研究.基于河床冲淤判别指标,筛选了小浪底水库运行前后黄河下游低含沙量条件下各水文断面处于冲淤相对平衡时的实测水沙要素,确定了挟沙力系指数与水沙综合参数的计算关系,并应用于黄河下游典型少沙年的水沙输移过程计算.结果表明:挟沙力系指数与水沙综合参数呈密切的函数关系,且随着水沙综合参数的增大逐渐减小并最终保持不变;对比了不同挟沙力模式下2017年黄河下游水沙输移过程的计算结果,当挟沙力系指数采用提出的计算式确定时,游荡段含沙量过程计算值与实测值符合较好,与挟沙力系指数取常数相比,各水文断面平均相对误差降低50%~67%.因此该计算式确定的挟沙力系指数能较好适应水沙条件的沿程变化,可以提高水沙数学模型的计算精度.The determination of parameters in the formula for sediment transport capacity will exert a significant effect on sediment transport processes.The formulae for sediment transport capacity mainly consider hyperconcentrated flows,which are currently applied in numerical simulation of sediment transport and channel evolution processes in the Yellow River.However,low concentrated floods occur frequently in the Lower Yellow River(LYR)after the operation of the Xiaolangdi Reservoir,and the applicability of these formulae is limited because the parameters are originally obtained based on hyperconcentrated flows before the reservoir operation.In this study,the hydrological data in the relative equilibrium state were collected from the hydrometric stations.Furthermore the calculation relations are determined between the parameters in the formula and the comprehensive parameter,which were then applied in the numerical modelling of the 2017 flood in the LYR.The results show that:(1)the coefficient and exponent of the formula proposed by H.W.Zhang show a negative power functional relationship with the comprehensive parameter,and reach constant values lastly;(2)comparisons are made among the simulated sediment concentration hydrographs calculated by three methods.The simulated hydrographs are in best agreement with the observations in the braided reach when the formula proposed in the study is adopted,with MAEs reducing by 50%and 67%at the stations of Jiahetan and Gaocun respectively.The formula established in the study can reflect the effects of flow and sediment dynamics,which can improve the accuracy of the one-dimensional morphodynamic model.

关 键 词：低含沙量 挟沙力计算 输沙平衡 悬移床沙质 参数确定 黄河下游 

分 类 号：TV143[水利工程—水力学及河流动力学]