长江中游水沙通量时空变化及河床冲淤分布特征  

Variation Characteristics of flow and Sediment Fluxes and Channel Evolution in the Middle Yangtze River

作　　者：郭率 刘鑫 周美蓉[3] 关见朝[4] GUO Shuai;LIU Xin;ZHOU Mei-rong;GUAN Jian-chao(River Basin Water Control Project Operation Management Center,China Three Gorges Corporation,Yichang 443100,Hubei Province,China;Bureau of Hydrology,Changjiang Water Resource Commission,Wuhan 430010,Hubei Province,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan,430072,Hubei Province,China;Department of Sediment Research,China Institute of Water Resources and Hydropower Research,Beijing 100048,China)

机构地区：[1]中国长江三峡集团有限公司流域枢纽运行管理中心,湖北宜昌443100 [2]长江水利委员会水文局,湖北武汉430010 [3]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [4]中国水利水电科学研究院泥沙研究所,北京100048

出　　处：《中国农村水利水电》2025年第1期39-46,共8页China Rural Water and Hydropower

基　　金：中国长江三峡集团有限公司科研项目(0704217);国家自然科学基金项目(U2040215,52109098)。

摘　　要：三峡及上游水库群运用后长江中游水沙条件发生显著变化,河床持续冲刷调整,因此有必要研究干支流水沙通量的时空变化特征及河床冲淤分布特点。基于干支流主要控制站实测水沙资料与平滩河槽冲淤量数据,详细分析了长江中游及各子河段水沙通量及冲淤量的时空变化规律。分析结果表明:(1)从时间尺度来看,三峡工程运用后中游干流年径流量变化不大,输沙量减少68%~92%。径流年内均呈汛期减小,枯水期增大的规律。除仙桃站年径流量和湖口站年输沙量增大外,其余支流和通江湖泊的水量和沙量均减小;(2)从空间尺度来看,径流量沿程变化未发生显著调整,但输沙量由三峡工程运用前的沿程减小调整为沿程增加,且泥沙来源由三峡工程运用前的上游输入为主(占比约为120%)调整为运用后的河床冲刷补给为主(占比为53%);(3)2002-2020年长江中游干流平滩河槽累计冲刷26.3亿m^(3),约占中下游总冲刷量的54%,尤以荆江段冲刷幅度最大(占比为47%),且冲刷重心由宜枝段向汉湖段移动;(4)建立了分河段累计冲淤量与对应控制站前5年汛期平均水流冲刷强度的函数关系,决定系数(R2)均高于0.8,定量反映了坝下游河床纵向调整对来水来沙条件变化的响应关系,可用于定量估算不同水沙条件下各河段的河床冲淤量。The regime of flow and sediment changed significantly after the operation of the Three Gorges Project(TGP)and its upstream reservoirs,which led to intensive channel degradation in the Middle Yangtze River(MYR).Therefore,it is necessary to investigate the temporal and spatial variation characteristics of the flow and sediment fluxes from the main stream and tributaries and channel evolution processes of the MYR.Based on the flow and sediment measurements at the hydrometric stations and the measured channel evolution volume corresponding to bankfull level,this study analyzed the temporal and spatial variations of the flow and sediment fluxes and channel evolution processes in the MYR.The results indicate that:①In terms of temporal variation,the annual runoff of the MYR has not changed much,while the sediment load decreased by 68%~92%after the TGP operation.The water runoff decreased during the flood seasons and increased during the dry seasons.Except for the increase of annual runoff at Xiantao station and sediment load at Hukou station,the annul fluxes of flow and sediment of other tributaries and lakes decreased;②In terms of spatial variation,the longitudinal change of runoff along the MYR did not show any significant adjustments.However,the longitudinal change of sediment load adjusted from a decrease to an increase along the MYR following the TGP operation,and the primary source of sediment changed from the upstream input prior to the TGP operation(accounting for about 120%)to the channel evolution after the TGP operation(accounting for 53%);③The cummulative erosion volume corresponding to bankfull level in the MYR was 2.63 billion m^(3) during the period 2002-2020,accounting for about 54%of the cummulative erosion volume in the middle and lower Yangtze River.Especiall,y the Jingjiang Reach suffered the most dramatic channel erosion(accounting for 47%),and the channel erosion center moved from the Yizhi Reach to the Hanhu Reach along the MYR.④Empirical functions were developed between the sub-reach’s

关 键 词：三峡工程 水沙通量 河床冲淤 时空变化 长江中游 

分 类 号：TV147[水利工程—水力学及河流动力学]