黄河干流沿程水沙变化及其影响因素分析

采用"中国河流泥沙公报"数据,结合流域内长系列年降水量资料,探讨黄河干流沿程水沙的历史变化情况。通过对17个雨量站长系列降水量资料的分析,认为气候不是黄河径流量变化的主要影响因素;黄河年径流量沿程降低,而且愈往下游降低的幅度愈大,这主要是引水量增加和水土保持措施引起的;中下游沙量明显降低,降低的幅度沿程增加,这主要是水土保持、水利枢纽建设及其对水沙量的调节、上游引水和气候变化等因素综合作用的结果,其中水利枢纽工程的兴建和水库运行方式的改变引起了沙量的突变。分析还表明,黄河利津站年水沙量自20世纪50年代的474亿m3和14亿t大幅度减少至2000年以来6年的平均值132亿m3和1.5亿t,给黄河口的演变带来很大的影响,值得深入研究。

Variation of flow and sediment of the Yellow River and their influential factors

Variation of flow and sediment along the main stream of the Yellow River is analyzed using the long-term data published in China Gazette of River Sedimentation and long-term precipitation data.Based on analysis of the precipitation depth of 17 gauge stations,it is concluded that precipitation depth has little influence on the runoff of the Yellow River.The annual runoff decreases along the river from upper to lower reaches,and the decrease is mainly caused by increasing water diversion from the Yellow River and water and soil conservation practices.The sediment content in middle and lower reaches has a clear downward trend.The decrease of sediment loads is caused by human activities such as water and soil conservation,construction and operation of reservoirs on the Yellow River,and water transfer and intake,as well as climate change.Sharp changes in sediment amount can be observed downstream of a reservoir when it is put into operation or when its regulation mode changes.The average annual runoff and sediment loads at Lijin gauge station,the most downstream station on the Yellow River,decreased from 47.4×109 m3 and 1.4×109 t of average values of 1950 s to 13.2×109 m3 and 0.15×109 t of average values of latest 6 years since 2000,respectively.The changes will have significant effects on the evolution of the Yellow River mouth.