荆江河段泥沙冲淤对三峡水库汛期排沙的响应  

Responses of erosion and deposition in the Jingjiang reach to sediment delivery of the Three Gorges Reservoir during flood season

作　　者：左利钦[1,2] 陆永军 王洪杨[1] 郑力 李鑫 ZUO Liqin;LU Yongjun;WANG Hongyang;ZHENG Li;LI Xin(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China;Yangtze Institute for Conservation and Development,Nanjing 210098,China;Changjiang Channel Survey and Design Institute(Wuhan)Co.Ltd.,Wuhan 430040,China)

机构地区：[1]南京水利科学研究院水文水资源与水利工程科学国家重点实验室,江苏南京210029 [2]长江保护与绿色发展研究院,江苏南京210098 [3]长江航道勘察设计院(武汉)有限公司,湖北武汉430040

出　　处：《水科学进展》2023年第1期115-125,共11页Advances in Water Science

基　　金：国家自然科学基金资助项目(52071221);国家青年人才资助项目(GO222001)。

摘　　要：三峡水库汛期排沙研究大多关注库区的减淤效应,对坝下游河道的冲淤影响尚需进一步研究,对优化水库调度和河道保护利用具有重要意义。以三峡水库下游荆江河段为对象,建立了荆江长河段二维水沙数学模型,并结合实测资料分析,基于三峡水库2018年7月排沙调度,通过设置不同的排沙比(7%~100%),计算分析了荆江河段冲淤对三峡水库排沙比的响应。结果表明:虽然荆江河段全年总体冲刷,但排沙比较大时汛期仍可能淤积,上荆江河段受排沙调度影响相对较大;总体而言,2018年汛期水沙条件下,30%左右的排沙比是荆江河段洪季冲淤的临界点;排沙比提高后,汛期淤积部位大部分为边滩等缓流区,以及弯曲河段凹岸等,主槽仍冲刷,对维护滩槽高差具有积极意义。Most studies on the sediment delivery of the Three Gores Reservoir(TGR) focus on the reduction of siltation in the reservoir area, while the impacts on the river bed evolution in the downstream reaches need further study.This study is of great significance for optimizing flow and sediment regulation as well as the protection and utilization of downstream reaches.The river bed evolution impacted by sediment delivery regulation during flood season in the Jingjiang reach was studied, which located downstream of the TGR.Combined with the measured data, a 2-D flow-sediment numerical model in the Jingjiang reach was established to calculate and analyze the erosion and deposition process by setting different sediment delivery ratios(7%—100%),based on the sediment delivery regulation in July 2018.The results showed that, although the Jingjiang reach was generally suffering an annual scouring process, it might still experience deposition in a flood season with a higher sediment delivery ratio of the TGR.Moreover, there were more influences of the sediment delivery regulation on the Upper Jingjiang reach;in general, the sediment delivery ratio of about 30% was basically the dividing point between the erosion and deposition of the Jingjiang reach during a flood season under the flow-sediment conditions in July 2018;during a flood season, deposition mainly happens in slow-flow areas on point bars and concave banks in curved reaches, but the main-flow zone still experiences erosion, which was positive for maintaining the elevation difference between shoals and channels.

关 键 词：排沙调度 场次洪水 水沙调节 泥沙冲淤 排沙比 荆江河段 三峡水库 

分 类 号：TV148[水利工程—水力学及河流动力学]