| 引用本文: | 张先毅,黄竞争,杨昊,欧素英,刘锋,蔡华阳,杨清书.长江河口潮波传播机制及阈值效应分析.海洋与湖沼,2019,50(4):788-798. |
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| 长江河口潮波传播机制及阈值效应分析 |
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张先毅1,2,3, 黄竞争1,2,3, 杨昊1,2,3, 欧素英1,2,3, 刘锋1,2,3, 蔡华阳1,2,3, 杨清书1,2,3
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1.中山大学海洋工程与技术学院 河口海岸研究所 广州 510275;2.河口水利技术国家地方联合工程实验室 广州 510275;3.广东省海岸与岛礁工程技术研究中心 广州 510275
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| 摘要: |
| 河口潮波传播过程受沿程地形（如河宽辐聚、水深变化）及上游径流等诸多因素影响，时空变化复杂。径潮动力非线性相互作用研究有利于揭示河口潮波传播的动力学机制，对河口区水资源高效开发利用具有重要指导意义。本文基于2007—2009年长江河口沿程天生港、江阴、镇江、南京、马鞍山、芜湖的逐日高、低潮位数据及大通站日均流量数据，统计分析不同河段潮波衰减率与余水位坡度随流量的变化特征，结果表明潮波衰减率绝对值与余水位坡度随流量增大并不是单调递增，而是存在一个阈值流量和区域，对应潮波衰减效应的极大值。为揭示这一阈值现象，采用一维水动力解析模型对研究河段的潮波传播过程进行模拟。结果表明，潮波传播的阈值现象主要是由于洪季上游回水作用随流量加强，余水位及水深增大，导致河口辐聚程度减小，而余水位坡度为适应河口形状变化亦有所减小，从而形成相对应的阈值流量和区域。 |
| 关键词: 长江河口 径潮相互作用 余水位坡度 潮波衰减率 阈值效应 |
| DOI：10.11693/hyhz20181200305 |
| 分类号:P731.23 |
| 基金项目:国家重点研发计划项目，2016YFC0402601号；国家自然科学基金项目，51709287号；河口海岸学国家重点实验室开放课题基金资助项目，SKLEC-KF201809号；广东省自然科学基金项目，2017A030310321号；高校基本科研业务费青年教师重点培育项目，171gzd12号。 |
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| THE GOVERNING MECHANISM OF TIDAL WAVE PROPAGATION AND THRESHOLD EFFECT IN THE CHANGJIANG RIVER ESTUARY |
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ZHANG Xian-Yi1,2,3, HUANG Jing-Zheng1,2,3, YANG Hao1,2,3, OU Su-Ying1,2,3, LIU Feng1,2,3, CAI Hua-Yang1,2,3, YANG Qing-Shu1,2,3
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1.Institute of Estuarine and Coastal Research, School of Marine Sciences, Sun Yat-sen University, Guangzhou 510275, China;2.State and Local Joint Engineering Laboratory of Estuarine Hydraulic Technology, Guangzhou 510275, China;3.Guangdong Provincial Engineering Research Center of Coasts, Islands and Reefs, Guangzhou 510275, China
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| Abstract: |
| Tides are modified by topography (such as channel width convergence and depth variation) and river discharge as they propagate into an estuary, resulting in a complex pattern in both temporal and spatial scales. Therefore, understanding the dynamic mechanism of tidal wave propagation and the process of nonlinear tide-river interactions in estuaries are important. We analyzed the spatial-temporal variations of the tidal damping and the residual water level slope as a function of river discharge based on the daily measurements of tidal water levels along the Changjiang (Yangtze) River estuary in 6 stations and the river discharge data in one station from 2007 to 2009. Results show that relationship of the river discharge to the tidal damping and the residual water level slope is nonlinear and there are a critical position along the channel and a critical river discharge corresponding to the maximum tidal damping. To reveal such a threshold effect, we used a well-developed one-dimensional hydrodynamic analytical model to reproduce the tidal dynamics along the river and in the estuary. The results show that the threshold effect was due mainly to the backwater effect that was enhanced with the increase of river discharge in the upper reach, where the effect of channel convergence was reduced with the rise of residual water level and water depth; and the critical position and river discharge would occur in response to the decrease of the residual water level slope as the estuary opens wide. |
| Key words: Changjiang River estuary tide-river interaction residual water level slope tidal damping threshold effect |
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