三峡工程运用后长江中游多断面水力几何关系变化特点  

Variation in the hydraulic geometry of the middle Yangtze River after the Three Gorges Project operation

作　　者：孙慧雯 夏军强[1] 邓珊珊[1] 周美蓉[1] SUN Huiwen;XIA Junqiang;DENG Shanshan;ZHOU Meirong(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430010,China)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,湖北武汉430010

出　　处：《武汉大学学报（工学版）》2024年第7期863-871,共9页Engineering Journal of Wuhan University

基　　金：国家自然科学基金项目(编号:52009095,U2040215);湖北省自然科学基金创新群体项目(编号:2021CFA029)。

摘　　要：三峡工程的运用改变了坝下游来水来沙条件,长江中游河床持续冲刷,河道水力几何关系相应调整。选取长江中游枝城-汉口河段作为研究对象,根据实测资料分析了2003—2017年长江中游不同断面的水力几何关系的变化特点。结果表明:1)三峡工程运用后,枝城-汉口河段的河道冲刷主要集中在枯水河槽,水面宽的调整也多集中于枯水河槽,同流量下水面宽的变化最高可达400 m,各站同流量下宽深比呈现出不同程度的减小;2)各水文站同流量下水深增大,流速减小;荆江河段河道冲刷强度较大,水深及流速与流量关系的变动范围较大;由于冲刷强度逐渐减弱,水深及流速与流量关系的变动幅度逐年减小,从第1阶段(2003—2006年)至第4阶段(2014—2017年)变动范围的减幅超过25%;城汉河段的河道冲刷强度较小,仅为荆江河段冲刷强度的54%,水深及流速与流量关系的变动范围也较小,逐年变化规律不明显。The operation of the Three Gorges Project(TGP)has changed the flow and sediment regimes in the river below the dam,the riverbed in the middle reaches of the Yangtze River(MYR)has been continuously scoured,and the hydraulic geometry of the MYR has been adjusted accordingly.The Zhicheng-Hankou subreach of the MYR was chosen as the research object,and the variation characteristics of hydraulic geometry of different sections in the MYR were analysed according to the measured data from 2003 to 2017.The results showed that:1)After the TGP operation,the bed erosion from Zhicheng to Hankou was mainly concentrated in the low-flow channel.The adjustment range of the water surface width was mainly concentrated in the low-flow channel,and the maximum variation in the width reached 400 m under the same discharge.The width-depth ratio at each station decreased under the same discharge.2)The water depth increased under the same discharge at each station,with the flow velocity decreasing.The bed erosion in the Jingjiang River reach is intensive,leading to a more significant variation in the range of water depth and the relationship between velocity and discharge.Due to the gradual weakening of scour intensity,the variation range of water depth and the relationship between velocity and discharge became smaller year by year,and the variation range decreased by more than 25%from PhaseⅠ(2003-2006)to PhaseⅣ(2014-2017).The erosion intensity in the Chenghan reach was small,only 54%of that of Jingjiang River reach.The variation ranges of water depth and the relationship between velocity and discharge were small,and the change law was not obvious year by year.

关 键 词：冲积河流水力学 水力几何关系 水沙条件 长江中游 三峡工程 

分 类 号：TV147.3[水利工程—水力学及河流动力学]