三峡工程运行以来长江南京河段河床演变特征分析  

Analysis of riverbed evolution characteristics of Nanjing reach in the Yangtze River since the operation of the Three Gorges Project

作　　者：王乃茹 曹双 王清 陈槐[1] 朱立俊[1] 范红霞[1] WANG Nairu;CAO Shuang;WANG Qing;CHEN Huai;ZHU Lijun;FAN Hongxia(Nanjing Hydraulic Research Institute,Nanjing 210024,Jiangsu,China;Survey Bureau of Hydrology and Water Resources of Lower Reaches of Changjiang River,Nanjing 210011,Jiangsu,China;Public Engineering Construction Center of Nanjing Jiangbei New District,Nanjing 211899,Jiangsu,China)

机构地区：[1]南京水利科学研究院,江苏南京210024 [2]长江水利委员会水文局长江下游水文水资源勘测局,江苏南京210011 [3]南京市江北新区公共工程建设中心,江苏南京211899

出　　处：《水利水电技术（中英文）》2022年第11期13-24,共12页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(52209095,52179072,52079080);南京水利科学研究院创新团队项目(Y220011)。

摘　　要：三峡工程运行改变了坝下游水沙条件,长江中下游包括南京河段的河床演变将出现新的动态变化。根据多年实测水沙及河道地形资料,在分析三峡工程运行以来南京河段来水来沙变化特点的基础上,对运行前后全河段河床冲淤及演变特征进行了探讨。结果表明:三峡工程运行以来,南京河段受来沙量锐减的影响,全河段呈普遍冲刷,并由运行前沿程“冲淤交替”变为“上淤、下冲”,尤以梅子洲汊道段和龙潭仪征水道段冲刷最为明显,冲淤形态具有“滩槽均冲”的特点。2001-2020年全河段累计冲刷泥沙近1.1亿m^(3),年均冲刷强度5.89万m^(3)/(km·a),其中2006-2020年冲刷强度为7.81万m 3/(km·a),较2001-2006年增大了近14倍。但在多年河道整治与护岸工程作用下,三峡工程运行后,南京河段河势总体基本稳定,局部河势有所调整,主要为上游小黄洲汊道汇流段岸线和深槽右摆、左汊分流比缓慢上升,引起新生洲右缘未护岸段冲刷崩岸;八卦洲洲头分流处深槽往右汊方向摆动,伴随左汊分流比持续降低;龙潭段的乌龙山边滩和兴隆洲心滩深槽冲刷发展。建议下一阶段加强原型观测,密切关注小黄洲汇流段河势变化对下游河段河势的影响,必要时对重点险工段、迎流顶冲段和护岸空白段等进行适当的工程措施。The operation of the Three Gorges Project has altered the conditions of water and sediment downstream of the reservoir.Consequently,the riverbed evolution of the middle and lower reaches of the Yangtze River(including Nanjing reach)will experience new dynamic changes.In this paper,based on the analysis of water and sediment changes of Nanjing reach after the Three Gorges Project impoundment and the measured water and sediment as well as topographic data,the characteristics of riverbed erosion/deposition and evolution of Nanjing reach before and after the impoundment were explored.The results show that after the Three Gorges Project impoundment,the Nanjing reach was generally eroded affected by the sharp decrease in sediment quantity,and showed a pattern of deposition in its upstream and erosion in its downstream,although before the impoundment,the riverbed was characterized by alternating erosion and deposition in the longitudinal direction.The feature of the erosion was that the floodplain and the main channel were eroded simultaneously with most of the erosion appearing in the reach of Meizizhou branch and Longtan-Yizheng waterway.From 2001 to 2020,the erosion amount was approximately 1.1×108 m^(3),with average annual erosion intensity being 5.89×104 m^(3)/(km·a),and the erosion intensity[7.81×104 m^(3)/(km·a)]from 2006 to 2020 was nearly 14 times higher than that of 2001 to 2006.Through years of channel regulation and bank-protection projects,the river regime of Nanjing reach was generally stable,with local regime adjustments somewhat.Firstly,the bank line and deep groove in the upstream Xiaohuangzhou confluence section swayed towards the right direction,accompanied by a gradual increase in the diversion ratio of the left branch of Xiaohuangzhou,which caused the local erosions and collapse in the unprotected section of the right edge of Xinshengzhou.Secondly,in the segment of Baguazhou branch,the deep groove in the vicinity of the bifurcation swayed towards the right branch,and the diversion ratio of the

关 键 词：长江下游 南京河段 河床冲淤 河床演变 三峡工程 

分 类 号：TV143[水利工程—水力学及河流动力学]