长江上游水流挟沙力与含沙量比值的变化规律  

Comparison of sediment carrying capacity to sediment concentration in upper reaches of Yangtze River

作　　者：刘尚武 王治力 李丹勋[1] LIU Shangwu;WANG Zhili;LI Danxun(State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《水力发电学报》2022年第11期46-55,共10页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金面上项目(51879138)。

摘　　要：水流挟沙能力与含沙量的相对大小是判断河床冲淤的主要指标。本文基于长江上游主要干支流控制性水文站2010—2020年实测水沙资料,采用张瑞瑾水流挟沙力公式,分别计算了各站的水流挟沙力,在此基础上分析了水流挟沙力与含沙量比值(S^(*)/S)的变化规律。结果表明:除部分位于库区水文站小流量时S*/S小于1外,其余S^(*)/S均大于1,表明长江上游河道总体呈不饱和输沙状态;除金沙江向家坝站外,其余各站S^(*)/S随流量均呈先增加后减少的趋势,存在一个极大值点;2013年以后长江干流朱沱站和寸滩站同一流量条件下S^(*)/S较2013年前偏大,而沱江富顺站和涪江小河坝站2013年以后同一流量条件下S^(*)/S较2013年前偏小。研究成果对认识山区河流输沙特性、提升河道冲淤演变的预测能力等具有一定的参考价值。The ratio of the sediment carrying capacity(S^(*))of a river flow to its local sediment concentration(S)serves as a direct indicator of topographic change in riverbed.We have collected the field data of the upper Yangtze measured at its major hydrological stations in 2010-2020,and conducted an analysis of the ratio S^(*)/S.The results show that with a few exceptions,the carrying capacity generally exceeded local sediment concentration,and S^(*)/S presented a first-increase-then-decrease pattern of variation with flow discharge.This pattern is closely related to upstream dam operation and earthquakes-e.g.,impoundment of the Xiluodu and Xiangjiaba reservoirs since 2013 led to an increase in S^(*)/S at the same flow discharge,while a decrease in S^(*)/S has been observed at the Xiaoheba and Fushun stations in recent years due to the gradually reducing effect of earthquakes.The findings in this study provide a new insight for understanding sediment transport and promoting channel regulation in mountainous rivers.

关 键 词：水流挟沙力 含沙量 流量 低水河槽 长江上游 

分 类 号：TV147[水利工程—水力学及河流动力学]