黄河宁夏段近期水沙特性及冲淤量变化预测

以1950年11月至2018年10月黄河宁夏段水沙系列资料为基础,运用统计法、经验公式法、断面法分析并预测该河道冲淤情况。结果表明,近年来黄河宁夏段水沙量明显减少,年内分配不均,小流量天数显著增加;河道有冲有淤、冲淤交替变化,多年冲淤基本平衡。河段年平均冲淤量的预测值为1993年~2018年的年实测大断面平均冲淤量0.082亿t,若按河段划分,其中沙坡头坝下至枣园年平均淤积157万m³,年平均淤积厚度为0.019 m;青铜峡坝下至石嘴山河段年平均淤积量428万m³,年平均淤积厚度为0.009 m。

Recent Water-sediment Characteristics and Prediction of Erosion and Siltation Change in the Ningxia Section of the Yellow River

Based on the water and sediment series data of the Ningxia section of the Yellow River from November 1950 to October 2018,the statistical methods,empirical formula methods and section methods are used to analyze the water-sediment characteristics of the Ningxia section of the Yellow River and predict the erosion and siltation of the river section.The results show that,in recent years,the amount of water and sediment in the river section has decreased significantly,the distribution is uneven during the year,and the number of days with small flows has increased significantly.The river channel has alternate changes in erosion and siltation,and the erosion and siltation have been basically balanced for many years.The predicted value of average annual siltation volume of the river section is 8.2 million tons that is the measured average annual erosion and siltation of the large section from 1993 to 2018 by section methods.The annual average siltation volumes of the section from lower Shapotou Dam to Zaoyuan and from lower Qingtongxia Dam to Shizuishan are 1.57 million m 3 and 4.28 million m³ respectively,and the annual average siltation thicknesses are 0.019 m and 0.009 m respectively.