摘要
航道浅滩演变与边心滩形态调整具有强关联性,叠加河道冲淤不均衡性、上游河段冲刷供沙等综合影响,使得航道浅滩碍航机制更趋复杂。本研究以长江感潮段内落成洲河段为对象,通过1959—2021年洲滩形态、河床冲淤特征、水动力环境与浅滩碍航特性等分析,明确边心滩—浅滩演变联动关系、上游河床冲刷供沙及对浅滩演变的影响机制。研究结果表明:①1981年以来落成洲河段所在的扬中河段由淤积转为1991年以来的持续冲刷,1981—2021年枯水河槽冲刷量为3.97亿m^(3),占洪水河槽冲刷量的95.9%;②三峡工程运行前嘶马弯道崩退—落成洲左缘淤积—三益桥边滩未发育,即嘶马弯道崩退是洲滩联动演变的主要诱因;③三峡工程运行后至航道整治工程实施前的来沙量减少引起洲滩整体冲刷,落成洲冲刷为三益桥边滩提供了发育空间,逐渐淤涨的三益桥边滩与水沙条件共同使得落成洲冲刷和右汊冲刷发展,即三益桥边滩形态变化逐渐由被动淤涨转为洲滩联动演变的主因;④1981—2010年三益桥边滩淤涨、落成洲洲头与左缘冲刷等决定着三益桥浅滩碍航程度,由于流域来沙量减少引起的河床冲刷使得碍航程度减弱,2011—2021年航道工程作用下的落成洲左缘边界逐渐稳定与下浅区航道条件得到改善,同时三益桥边滩面积由淤积转为小幅冲刷,航道碍航位置逐渐上提形成上浅区;⑤二期工程实施以来,流域来水过程条件、三益桥边滩冲刷和落成洲右汊相对发展等变化仍不利于落成洲河段前滩段航道条件的稳定,建议后续完善工程中采取稳定洲滩边界与限制右汊冲刷发展的工程措施。
There is a strong correlation between waterway shoal evolution and boundary shoal morphology adjustment.Combining with effects of unbalanced channel scouring and distribution,scouring and sediment supply of upper reaches,these make waterway shoal obstruction mechanism more complicated.In this study,the Luochengzhou reach in the tidal reach of Yangtze River is taken as the object.By analyzing the morphology of the shoal,the characteristics of riverbed scouring and deposition,the hydrodynamic environment and the navigation-obstructing characteristics of the central bar and beach during 1959—2021,we clarified the linkage relationship between the evolution of the central bar and beach the waterway shoal,and the scouring and sediment supply of the upstream riverbed and its influence mechanism on the evolution of the waterway shoal.Since 1981,the Yangzhong reach where the Luochengzhou reach is located has changed from siltation to continuous scouring since 1991.The scouring amount of the lowwater channel from 1981 to 2021 is 3.97×10^(8) m^(3),accounting for 95.9%of the flood channel scouring volume;before the operation of the Three Gorges Project,the collapse of Sima bend area,the siltation of the left margin of Luochengzhou,and the undeveloped of the Sanyiqiao beach are the chief reasons for the collapse of Sima bend area.After the operation of the Three Gorges Project and before the implementation of the waterway regulation works,the decrease of sediment inflow caused the overall erosion of the shore,and the scouring of Luochengzhou provided the development space for the Sanyiqiao beach,the gradually silted Sanyiqiao beach and the runoff and sediment conditions jointly led to the development of the scouring of Luochengzhou and the right branch,that is,the change of the shape of the Sanyiqiao beach gradually changed from passive siltation to the main cause of the intertidal evolution.During 1981—2010,the sedimentation of Sanyiqiao beach,the erosion of the head and left edge of the Luochengzhou reach determined th
作者
杨云平
张夏博
郑金海
朱玲玲
王建军
方娟娟
魏稳
YANG Yunping;ZHANG Xiabo;ZHENG Jinhai;ZHU Lingling;WANG Jianjun;FANG Juanjuan;WEI Wen(Tianjin Research Institute for Water Transport Engineering,Ministry of Transport,Tianjin 300456,China;Hohai University,Nanjing 210098,China;Bureau of Hydrology Changjiang Water Resources Commission,Wuhan 430010,China;Changjiang River Scientific Research Institute,Wuhan 430019,China;School of Marine Science and Technology Sun Yat-sen University,Zhongshan 528406,China)
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2023年第2期250-264,共15页
Advances in Water Science
基金
国家自然科学基金资助项目(52279066,U2240206)。
关键词
洲滩变形
航道条件
浅滩演变
驱动机制
落成洲河段
长江下游
central bar and beach deformation
waterway conditions
waterway shoal evolution
driving mechanism
Luochengzhou reach
lower reach of Yangtze River
