黄河上游水沙变化及成因分析

Analysis of water and sediment changes in Upper Yellow River

利用黄河上游的实测资料,以头道拐断面为主要研究对象,从径流泥沙的年际变化、年内分配、洪水特征等方面分析了上游水沙变化特点,突变点为刘家峡和龙羊峡水库投入运用时间。对不同影响因素的研究认为,天然径流量的减少和耗水量的增加是造成上游水量减少的直接原因,龙羊峡和刘家峡水库的调节使天然的年内径流量重新分配,水库的削峰作用和调节流量过程,造成了水库下游洪峰流量的大幅度减小和流量过程的均匀化,从而对河道输沙产生十分不利的影响。正确认识水沙变化产生的原因及其带来的负面影响,可为水资源的合理开发、上游宁蒙河道的综合治理提供参考。

Based on the measured data of Toudaoguai hydrological station,the water and sediment changes are analyzed through the yearly runoff and sediment changes,distributions within a year,and the characteristics of floods and so on.The result shows the turning points of the changes were the years when the Liujiaxia reservoir and Longyangxia reservoir were put into operation respectively.The decrease of natural runoff and the increase of water consumption are the direct reasons for the decrease of incoming runoff in the upper Yellow River.The runoff is reallocated by the regulation of the Liujiaxia and Longyangxia reservoirs.Flattening the flood peak and regulating the water discharge cause the remarkable decline in the flood peak and homogenization of the flow in the downstream of the reservoirs,which has obvious negative effect on sediment transport.To learn the reasons of the water and sediment changes and the negative effect caused by them can provide reference for the appropriate water resources exploitation and the comprehensive treatment to the Ningmeng reach of the Upper Yellow River.