长江口主要分潮振幅时空变化特征及原因初探  

Preliminary exploration of the spatiotemporal variation characteristics and causes of the main tidal amplitude in the Yangtze Estuary

作　　者：王佑铭 沈淇 李俊花 顾峰峰 贾雨少 应铭 WANG Youming;SHEN Qi;LI Junhua;GU Fengfeng;JIA Yushao;YING Ming(Shanghai Estuarine&Coastal Engineering Consultants Ltd.,Shanghai 201201,China;Key Laboratory of Estuarine&Coastal Engineering,Ministry of Transport,Shanghai Estuarine&Coastal Science Research Center,Shanghai 201201,China;College of Ocean Science and Engineering,Shanghai Maritime University,Shanghai 201306,China;CCCC Shanghai Waterway Engineering Design and Consulting Co.,Ltd.,Shanghai 200120,China)

机构地区：[1]上海河口海岸工程咨询有限公司,上海201201 [2]上海河口海岸科学研究中心交通部河口海岸重点实验室,上海201201 [3]上海海事大学海洋科学与工程学院,上海201306 [4]中交上海航道勘察设计研究院有限公司,上海200120

出　　处：《水利水运工程学报》2025年第1期25-36,共12页Hydro-Science and Engineering

基　　金：上海市2021年度“科技创新行动计划”社会发展科技攻关项目(21DZ1201000)。

摘　　要：径潮流相互作用及河口拦门沙综合影响下,长江口潮波传播过程及内在机制十分复杂。以“下游口门-北槽拦门沙-上游徐六泾”段沿程6个潮位站多年逐时潮位、北槽洪、枯季水文及上游大通站流量资料,采用t-tide分析工具与河道阻力系数公式,重点分析长江口主要分潮(M2、S2、N2、K1、O1、M4)振幅受径流及河口拦门沙影响下的时空变化特征及成因。研究表明,外海潮波自口门传入口内,长江口各主要天文分潮振幅呈先增后减的特征,浅水分潮(M4)振幅逐渐增大。径流对分潮振幅影响的正向作用表现为其引起的局地水位抬升使分潮振幅增加,反向作用体现为其与潮流顶冲使分潮振幅减小。由于长江口各水域受径潮流正、反作用影响的占比差异,所以越靠近口内(外),径流对分潮振幅的反(正)向作用越显著。在两者之间的拦门沙过渡水域,分潮振幅(M2)随径流增加而呈现“先增后减”的变化趋势,临界径流量约为45 000 m^(3)/s。最大天文分潮振幅位于河口拦门沙水域,且洪季拦门沙水域分潮振幅沿程衰减速率小于枯季。洪季拦门沙近底高含沙量减阻效应对长江口潮波传播的影响不可忽略。The process and intrinsic mechanism of tidal wave propagation in the Changjiang Estuary are very complex under the interaction of tidal current and the comprehensive impact of sediment trapping at the river mouth.Using long-term hourly tidal level data,North Channel flood and drought hydrological data,and upstream Datong flow data from six tidal gauge stations along the"downstream estuary gate-North Channel sediment trapping-upstream Xuliujing"section,the t-tide analysis tool and channel resistance coefficient formula were used to analyze the spatial and temporal variations and causes of the amplitudes of the main tidal constituents(M2,S2,N2,K1,O1,M4)in the Changjiang Estuary under the influence of runoff and sediment trapping at the river mouth.The study shows that the amplitudes of the major astronomical constituents in the Changjiang Estuary exhibit a characteristic of first increasing and then decreasing as the tidal waves enter the estuary from the open sea,and the amplitude of the shallow water constituent(M4)gradually increases.The positive effect of runoff on the amplitude of the tidal constituents is manifested by the local water level rise caused by runoff,which increases the amplitude of the tidal constituents,while the negative effect is reflected by the interaction between runoff and tidal currents,which reduces the amplitude of the tidal constituents.Due to the difference in the proportion of positive and negative effects of runoff and tidal currents in different water areas of the Changjiang Estuary,the negative(positive)effect of runoff on the amplitude of the tidal constituents becomes more significant as it gets closer to the estuary(outer estuary).In the transitional water area between the two,the amplitude of the tidal constituent(M2)shows a"first increasing and then decreasing"trend with the increase of runoff,and the critical runoff is approximately 45,000 m^(3)/s.The maximum amplitude of the astronomical constituents is located in the sediment trapping area at the river mouth,and the amplit

关 键 词：长江口 分潮振幅 时空变化 调和分析 河道阻力 

分 类 号：P731.2[天文地球—海洋科学]