余水位即潮周期内的平均水位,是河口径潮动力非线性作用的典型结果。为探究径流、潮汐及其相互作用对余水位的影响,对摩阻项进行分解,通过潮平均摩阻的各分量对余水位的变化展开研究。采用二维水动力数学模型,模拟得到长江口余水位时空变化特征;利用连续小波变换方法和摩阻计算公式,分析长江口潮平均摩阻的主要来源,建立线性回归模型,通过潮平均摩阻各分量的变化解释余水位的变化。研究结果表明:长江口余水位具有明显的洪枯季变化和大小潮变化特征,洪季余水位沿程增幅更大,大潮时余水位较小潮时更高;长江口潮平均摩阻以径流作用和径潮相互作用产生的摩阻为主,因径流量巨大,前者对潮平均摩阻的贡献始终更大;潮平均摩阻控制余水位,长江口余水位的变化由径流作用控制,在下游站点径潮相互作用的影响不可忽视。
Abstract
The average water level during tidal cycle, also known as the residual water level, is a typical outcome resulting from the nonlinear interaction between tides and river flow. To quantify the contributions of runoff, tides, and their interactions to the change of residual water level, the friction term is decomposed, and the components of mean tidal friction are examined to study the variations in residual water level. A two-dimensional numerical model is employed to simulate the hydrodynamic conditions and spatiotemporal characteristics of the residual water level in the Yangtze River Estuary. The continuous wavelet transform method togerther with the friction calculation formula is used to examine the primary sources of tidally averaged friction. Furthermore, a linear regression model equation is established to explain the variations in the residual water level. The results indicate that the residual water level in the Yangtze River Estuary exhibits distinct characteristics between wet and dry seasons and throughout the spring-neap cycle. Wet season experiences a more pronounced increase in the residual water level, particularly during spring tides. Tidally averaged friction is predominantly influenced by the river flow term and river-tide interaction term, with the contribution from river discharge consistently being greater due to its substantial volume. Tidally averaged friction governs the behavior of the residual water level. The variation in residual water level in the Yangtze River Estuary is primarily controlled by river flow; however, the influence of river-tide interactions cannot be ignored at downstream stations.
关键词
余水位 /
径潮相互作用 /
潮平均摩阻 /
连续小波变换 /
线性回归 /
长江口
Key words
residual water level /
river-tide interaction /
tidally averaged friction /
continuous wavelet transform /
linear regression /
Yangtze River Estuary
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参考文献
[1] 黄竞争, 张先毅, 吴 峥, 等. 长江感潮河段潮波传播变化特征及影响因素分析[J]. 海洋学报, 2020, 42(3): 25-35.
[2] LEBLOND P H. Forced Fortnightly Tides in Shallow Rivers[J]. Atmosphere-Ocean, 1979, 17(3): 253-264.
[3] GODIN G. The Propagation of Tides up Rivers with Special Considerations on the Upper Saint Lawrence River[J]. Estuarine, Coastal and Shelf Science, 1999, 48(3): 307-324.
[4] BUSCHMAN F A, HOITINK A J F, VAN DER VEGT M, et al. Subtidal Water Level Variation Controlled by River Flow and Tides[J]. Water Resources Research, 2009, 45(10): 5803-5804.
[5] SASSI M G, HOITINK A J F. River Flow Controls on Tides and Tide-Mean Water Level Profiles in a Tidal Freshwater River[J]. Journal of Geophysical Research: Oceans, 2013, 118(9): 4139-4151.
[6] BAO S, ZHANG W, QIN J, et al. Peak Water Level Response to Channel Deepening Depends on Interaction between Tides and the River Flow[J]. Journal of Geophysical Research: Oceans, 2022, 127: (4): 1-16.
[7] JAY D A, FLINCHEM E P. Interaction of Fluctuating River Flow with a Barotropic Tide: a Demonstration of Wavelet Tidal Analysis Methods[J]. Journal of Geophysical Research: Oceans, 1997, 102(C3): 5705-5720.
[8] JAY D A, KUKULKA T. Revising the Paradigm of Tidal Analysis-the Uses of Non-Stationary Data[J]. Ocean Dynamics, 2003, 53(3): 110-125.
[9] GUO L, VAN DER WEGEN M, JAY D A, et al. River-Tide Dynamics: Exploration of Nonstationary and Nonlinear Tidal Behavior in the Yangtze River Estuary[J]. Journal of Geophysical Research: Oceans, 2015, 120(5): 3499-3521.
[10]MATTE P, JAY D A, ZARON E D. Adaptation of Classical Tidal Harmonic Analysis to Nonstationary Tides, with Application to River Tides[J]. Journal of Atmospheric and Oceanic Technology, 2013, 30(3): 569-589.
[11]刘晓婉, 夏玉强, 李海龙, 等. 径流与潮汐对崇明岛南部近岸水位影响机制研究[J]. 工程勘察, 2015, 43(12):37-42, 54.
[12]郭磊城, 朱春燕, 何 青, 等. 长江河口潮波时空特征再分析[J]. 海洋通报, 2017, 36(6):652-661.
[13]杨正东, 朱建荣, 宋云平, 等. 长江口余水位时空变化及其成因[J]. 华东师范大学学报(自然科学版), 2021(2): 12-20.
[14]宋永港, 朱建荣, 吴 辉. 长江河口北支潮位与潮差的时空变化和机理[J]. 华东师范大学学报(自然科学版), 2011(6): 10-19.
[15]徐宇程, 朱首贤, 张文静, 等. 长江大通站径流量的丰平枯水年划分探讨[J]. raybet体育在线
院报, 2018, 35(6):19-23.
[16]ZHANG W, FENG H, HOITINK A J F, et al. Tidal Impacts on the Subtidal Flow Division at the Main Bifurcation in the Yangtze River Delta[J]. Estuarine, Coastal and Shelf Science, 2017, 196: 301-314.
[17]章卫胜. 中国近海潮波运动数值模拟[D]. 南京: 河海大学,2005.
[18]FARGE M. Wavelet Transforms and Their Applications to Turbulence[J]. Annual Review of Fluid Mechanics, 1992, 24(1):395-458.
[19]KUMAR P, FOUFOULA-GEORGIOU E. Wavelet Analysis for Geophysical Applications[J]. Reviews of Geophysics, 1997, 35(4): 385-412.
基金
国家自然科学基金长江水科学研究联合基金重点支持项目(U2040203);河海大学中央高校基本科研业务费专项资金(B210202026, B210205007)
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