黄河下游游荡河段高含沙洪水期输沙规律研究

Study on Regularity of Sediment Transport During Hyper-Concentrated Flood Periods in the Wandering Section of the Lower Yellow River

黄河下游河床长期处于淤积抬升状态,其冲淤演变规律对于下游河道治理有着重要影响。因此,快速预测不同量级高含沙洪水各河段的冲淤量以及判断高含沙洪水期黄河下游游荡河段冲淤影响很有必要。根据1960—2021年54场高含沙洪水的实测水沙资料,分析高含沙洪水期黄河下游游荡河段下站输沙率与上站流量、含沙量、输沙率之间的相关关系并建立关系式,系统地研究高含沙洪水的输沙规律。结果表明,下站输沙率与上站输沙率存在极强的相关性,进一步按来沙系数分级得到高含沙洪水期的输沙率公式,能够很好地模拟冲淤过程,极大地提高了与实测水沙资料的贴合度。以小浪底水文站为黄河下游游荡河段的进口控制水文站,采用按来沙系数分级所求的输沙率关系式能够较准确推求花园口站、夹河滩站、高村站的输沙率,从而计算小浪底—花园口、花园口—夹河滩和夹河滩—高村河段的累计冲淤量。

The river bed in the lower reaches of the Yellow River has been in a state of siltation and uplift for a long time,and the evolution law of erosion and deposition has an important influence to the treatment of the lower reaches.Therefore,it is necessary to quickly predict the erosion and deposition amount of different levels of high sediment content flood and judge the impact of wandering channels on the lower Yellow River during high sediment content flood period.Based on the measured water and sediment data of 54 floods with high sediment con-tent from 1960 to 2021,the correlation between the sediment transport rate of the lower Yellow River and the discharge,sediment content and sediment transport rate of the upper Yellow River was analyzed,and the correlation formula was established to systematically study the sedi-ment transport law of high sediment content flood.The results show that there is a very high correlation between the sediment transport rate of the lower station and the sediment transport rate of the upper station.The sediment transport rate formula of the flood period with high sedi-ment content can be obtained according to the classification of the sediment arrival coefficient,which can simulate the erosion and deposition process well and greatly improve the accuracy of the measured water and sediment data.Taking Xiaolangdi Hydrographic Station as the inlet control hydrographic station of the lower Yellow River,the sediment transport rates of Huayuankou Station,Jiahetan Station and Gaocun Sta-tion can be calculated by using the sediment transport rate relation formula,which is obtained by the classification of sediment intake coeffi-cient,so as to calculate the cumulative erosion and deposition of Xiaolangdi-Huayuankou,Huayuankou-Jiahetan and Jiahetan-Gaocun reach.