黄河下游河道11月至次年5月时期输沙和冲淤规律研究

Study on regularity of sediment transport and sedimentation in the Lower Yellow River during November to May next year

利用1960-2010年黄河下游11月至次年5月时期实测水沙资料,系统地研究了黄河下游河道水沙运动和河床冲淤规律。分析了花园口、高村、艾山和利津等4站输沙率与各自上站的流量、含沙量和输沙率的关系,黄河下游河道冲淤量与小浪底站来水量、来沙量、含沙量和来沙系数之间的关系。结果表明:黄河下游河道的下站输沙率与上站输沙率有很好相关关系,该时期进入黄河下游河道的输沙量小于1.82亿t、或平均含沙量小于12.6kg/m3、或来沙系数小于0.014 kg·s/m6时,下游河道以冲刷为主,反之则以淤积为主;采用本文建立的下站输沙率与上站输沙率关系式计算的黄河下游各河段冲淤量具有较高的精度。利用本文建立的关系式可以方便地预测未来黄河下游河道该时期不同河段冲淤量,对快速判断黄河上中游水利工程建设对下游河道冲淤影响具有重要意义。

Based on the obserled data of flow and sediment in the lower Yellow River during November to May next year from 1960 to 2010,a study on the regularity of flow-sediment movement and sedimentation in the lower Yellow River in this period is presented. The relationship between sediment transport rate at the four stations(Huayuankou,Gaocun,Aishan and Lijin) and the flow discharge,sediment concentration and sediment coming coefficient(S/Q) at their nearest upper station are analyzed. Also,the relationship between the sedimentation in the lower Yellow River and the runoff,sediment load,sediment concentration and sediment coming coefficient at Xiaolangdi station are established. The results show that the sediment transport rate at a given station has a good relationship with that at its closest upper station;when the sediment load is less than 182 x106 t,or the average sediment concentration is less than 12.6 kg/m3 or the sediment coming coefficient is less than 0.014 kg/s/m6 at Xiaolangdi station during this period,the erosion is dominant in the lower Yellow River,whereas the deposition is dominant;and the calculated sedimentation amount for each section of the lower Yellow River by using the proposed relationship in this paper has a high accuracy comparing with the obserled data. The relationship established in this paper can be easily used to estimate the sedimentation in the lower Yellow River during November to May next year,which is significant for quickly judging the effect of reservoir operation upstream on river bed variation in the lower Yellow River.