珠江河网典型横向汊道径潮动力时空差异性分析--以“南沙—南华”横向汊道为例  

Spatial-temporal variations in tide-river dynamics of typical transverse channel in the Pearl River channel networks--Taking the‘Nansha-Nanhua’transverse channel as an example

作　　者：邱秀芳 李博 王博芝 古俊豪 王辑思 苏雅楠 蔡华阳 QIU Xiufang;LI Bo;WANG Bozhi;GU Junhao;WANG Jisi;SU Yanan;CAI Huayang(Institute of Estuarine and Coastal Research,School of Ocean Engineering and Technology,Sun Yat-sen University,Guangzhou 510275,China;State and Local Joint Engineering Laboratory of Estuarine Hydraulic Technology,Guangzhou 510275,China;Guangdong Provincial Engineering Research Center of Coasts,Islands and Reefs,Guangzhou 510275,China;Southern Laboratory of Ocean Science and Engineering(Zhuhai),Zhuhai 519000,China)

机构地区：[1]中山大学海洋工程与技术学院,河口海岸研究所,广东广州510275 [2]河口水利技术国家地方联合工程实验室,广东广州510275 [3]广东省海岸与岛礁工程技术研究中心,广东广州510275 [4]南方海洋科学与工程广东省实验室(珠海),广东珠海519000

出　　处：《热带海洋学报》2023年第4期77-90,共14页Journal of Tropical Oceanography

基　　金：国家自然科学基金项目(51979296、52279080);广州市科技计划项目(202002030452)。

摘　　要：横向汊道对维持珠江河网径潮动力格局的稳定发挥着重要作用,研究其径潮动力时空演变过程及规律对粤港澳大湾区的防洪、供水和通航等具有重要意义。本文基于1966—2016年“南沙—南华”横向汊道沿程潮位站的逐日高低潮位数据及马口、三水水文站的日均流量数据,采用双累积曲线方法及T_TIDE潮汐调和分析模型,分析了该横向汊道径潮动力的时空差异性。结果表明:(1)1993年为该横向汊道径潮动力的异变年份,1993年后横向汊道潮波振幅梯度绝对值与余水位梯度多年均值降幅分别为25%和38%;(2)强人类活动干预后该横向汊道径潮动力变化存在时空差异性,1993年后口门南沙站潮动力减弱(M2与K1分潮振幅多年平均降幅分别为0.01m和0.02m),其他站点潮动力增强,潮波衰减效应在中游略有增强,而在上游和下游减弱,且夏季比冬季变化显著;(3)上述时空差异性受自然变化与人类活动的非线性累积影响。口门附近高强度的围垦叠加航道整治工程使得口门快速延伸,导致潮波传播阻力增大,而横向汊道上游高强度的采砂活动使得地形显著下切,导致潮波传播阻力减小;受上游流量与下游海平面季节性变化的叠加影响,横向汊道径潮动力变化在夏季比冬季更为显著。上述横向汊道径潮格局的异变导致其泄洪纳潮功能发生改变,具体表现为洪季泄洪压力减小,枯季纳潮能力增强。上述研究结果可为珠江三角洲水资源的高效开发利用等实际工程问题提供理论支撑。The transverse channel plays an indispensable role in the maintenance of dynamic equilibrium of the Pearl River channel networks.Therefore,studying the spatial-temporal variations in river-tide dynamics has important implications for flood control,water supply and navigation in the Guangdong-Hong Kong-Macao Greater Bay Area.Based on the high and low water level series observed at tidal gauging stations along the typical transverse channel(i.e.,‘Nansha-Nanhua’reach)and the daily averaged river discharge series observed at Makou and Sanshui hydrological stations from 1966 to 2016,the double cumulative curve method and the T_TIDE tidal harmonic analysis model were adopted to quantify the spatial-temporal variations in tide-river dynamics in the transverse channel.The results show that the tide-river dynamics in the transverse channel changed considerably in 1993,the annual mean absolute value of the tidal amplitude gradient and the annual mean value of the residual water level slope decrease by 25%and 38%,respectively;the tidal dynamics in the Nansha station at the estuary mouth weakens(the amplitudes of M2 and K1 constituent decreased by 0.01 m and 0.02 m on average,respectively),while the tidal dynamics at other stations enhanced after 1993.Meanwhile,the tidal damping effect slightly increased in the central reach,but decreased in both the upstream and downstream reaches,in which the alteration is more significant in summer than that in winter.This suggests that the dependence of the tidal amplitude gradients of two main constituents on the river discharge is significantly decreased.The phenomenon mentioned above can be mainly attributed to the nonlinear cumulative influence of natural changes and human activities.On the one hand,the combined influences of intensive reclamation and waterway regulation near the estuary mouth lead the rapid extension of the estuary mouth,which can result in an increase in the friction for tidal wave propagation.On the other hand,the intensive sand excavation in the upper reaches

关 键 词：流量 潮波振幅梯度 余水位梯度 径潮相互作用 强人类活动 

分 类 号：P735.51[天文地球—海洋生物学]