三峡工程蓄水后长江中游城陵矶-汉口河段过流能力变化及影响因素分析  

Variation in flood-discharge capacity of Chenglingji-Hankou reach in the middle Yangtze River and analysis of influencing factors since the onset of the Three Gorges Reservoir

作　　者：姚记卓 夏军强[1] 邓珊珊[1] 周美蓉[1] 许全喜 Yao Jizhuo;Xia Junqiang;Deng Shanshan;Zhou Meirong;Xu Quanxi(:State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,P.R.China;Bureau of Hydrology,Changjiang Water Resources Commission,Wuhan 430010,P.R.China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072 [2]长江水利委员会水文局,武汉430010

出　　处：《湖泊科学》2021年第3期830-841,共12页Journal of Lake Sciences

基　　金：国家重点研发计划项目(2016YFC0402303);国家自然科学基金项目(51725902,U2040215,52009095)联合资助。

摘　　要：受上游水库运行的影响,自2003年后长江中游河段河床调整,引起河道自身过流能力的变化.本文选取长江中游城陵矶-汉口河段作为研究对象,根据实测资料计算了2003-2016年两个水文断面的水位-流量关系及特征流量变化,并采用一维水动力学模型计算了河段尺度的平滩流量.结果表明:(1)螺山站及汉口站2003-2016年的水位-流量关系呈现枯水流量下水位降低、洪水流量下水位抬升的特点;(2)两站年最大流量下对应的水位整体抬升,警戒水位下对应的流量分别减小9%和16%;(3)2003-2016年城汉河段平滩流量有增有减,无明显单向变化趋势,2014年后呈减小趋势.分析断面的过流能力变化,发现螺山站与汉口站警戒流量与动床阻力呈明显的反比关系,过流能力由于河道阻力的增大而减小;床沙粗化、河道相对水深的减小及洲滩植被覆盖度的增大是引起河道阻力增大、过流能力减小的原因.Since the onset of the Three Gorges Project(TGP)in 2003,the sediment load entering the middle Yangtze River(MYR)has been reduced sharply,leading to remarkable channel degradation,which greatly influenced the flood-discharge capacity of this reach.In order to have a better grasp on this situation,there is a need to investigate the variation in flood discharge capacity in this area.Therefore,Chenglingji-Hankou reach(CHR)of the MYR was chosen as a typical reach for this study.Based on the cross-section profiles and hydrologic data surveyed annually from 2003 to 2016,the variations in the relationship between discharge and water-level,the corresponding water-level under the maximum discharge annually,and the characteristics of discharges under certain stages were analyzed at Luoshan and Hankou Stations.The results show that:(ⅰ)water-level under the same discharge decreased in dry season and changed slightly in flood season;water-level under the annual maximum discharge increased compared with that from 1954 to 2002;(ⅱ)the relative discharge under warning water-level at Luoshan and Hankou Stations decreased by 9%and 16%,respectively;(ⅲ)There is no obvious trend in the temporal variation of reach-scale bankfull discharge.The influence factors of the variation in the section-scale flood-discharge capacity were analyzed.It was found that the discharges under the warning water level(at Luoshan and Hankou Stations)were negatively correlated with the bed roughness,which implies that the increase in river resistance is probably one of the main causes of the variation in discharge capacity.Besides,the decrease in relative water-depth ratio and the increase in vegetation coverage on central bars may also show obvious influences on the discharge capacity of the study reach.

关 键 词：过流能力 河槽形态 河道阻力 城汉河段 长江中游 

分 类 号：TV147[水利工程—水力学及河流动力学]