下荆江七弓岭弯道裁弯的水情效应研究  

Hydrological Regime Effect of Qigongling Bend Cut-off inthe Lower Jingjiang River

作　　者：易放辉 彭赤彬 李觅 卢翔 郭小虎[3] 栾震宇[4] 李洪翔 YI Fang-hui;PENG Chi-bin;LI Mi;LU Xiang;GUO Xiao-hu;LUAN Zhen-yu;LI Hong-xiang(Hunan Provincial Xiangshui Group Co.,Ltd.,Changsha 410004,China;Hunan Water Resources and Hydropower Survey,Design,Planning and Research Co.,Ltd.,Changsha 410007,China;Key Laboratory of Ministry of Water Resources on River&Lake Regulation and Flood Control in Middle and Lower Reaches of Yangtze River,Changjiang River Scientific Research Institute,Wuhan 430010,China;Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]湖南省湘水集团有限公司,长沙410004 [2]湖南省水利水电勘测设计规划研究总院有限公司,长沙410007 [3]长江科学院水利部长江中下游河湖治理与防洪重点实验室,武汉430010 [4]南京水利科学研究院,南京210029

出　　处：《长江科学院院报》2023年第5期15-21,共7页Journal of Changjiang River Scientific Research Institute

基　　金：湖南创新型省份建设重点研发专项(2020SK2129);湖南省重大水利科技项目(XSKJ2019081-05,XSKJ2021000-01)。

摘　　要：三峡水库蓄水运用以来,下荆江七弓岭弯道段出现凸岸侧冲刷、凹岸侧淤积的现象,八姓洲狭颈宽度因崩岸缩短,存在裁弯的风险。基于原型观测资料,分析七弓岭弯道裁弯具体位置,设计裁弯新河道,建立长江中游-洞庭湖一二维耦合非恒定流模型,评估典型工况下七弓岭弯道裁弯带来的水情效应。结果表明,七弓岭弯道裁弯将造成汛期高洪水位下城陵矶水位升高0.03~0.04 m,枯期藕池口分流比减少0.09%、断流天数增加5 d,监利站月均水位下降0.04~0.11 m、七里山站月均水位上升0.01~0.04 m等影响。研究成果可为判断城陵矶附近防洪形势及提出相关应急预案提供技术支撑,对保障区域防洪安全及江湖汇流段治理和防护具有参考价值。Since the Three Gorges Reservoir began impounding water,the Qigongling bend in lower Jingjiang River has experienced convex bank erosion and concave bank deposition.The narrowing of the Baxingzhou section due to bank collapses has created a risk of river channel cut-off.Drawing on observation data,we analyzed the precise location of the cut-off in the Qigongling bend,designed a new cut-off channel,and established a 1D-2D coupled,non-steady flow model covering the Dongting Lake and the middle reaches of the Yangtze River to assess the hydraulic effects of the cut-off under typical operating conditions.Results reveal that the cut-off at Qigongling bend will have a considerable impact on the water levels in upstream and downstream river sections and Chenglingji,the flow diversion and zero-flow days at the three outlets of Jingjiang River,as well as the confluence relationship between Jingjiang River and Dongting Lake.Our study provides technical support for assessing flood prevention measures near Chenglingji and for proposing relevant emergency plans.It is of reference value for safeguarding flood control safety in the region and managing and protecting the confluence area of the Jingjiang River and the Dongting Lake.

关 键 词：弯道裁弯 水情效应 数值模拟 非恒定流模型 七弓岭弯道 

分 类 号：TV143[水利工程—水力学及河流动力学]