气候变化领域集成服务门户(CCPortal): Seasonal behaviour of tidal damping and residual water level slope in the Yangtze River estuary: Identifying the critical position and river discharge for maximum tidal damping

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DOI	10.5194/hess-23-2779-2019
	Seasonal behaviour of tidal damping and residual water level slope in the Yangtze River estuary: Identifying the critical position and river discharge for maximum tidal damping
	Cai H.; Savenije H.H.G.; Garel E.; Zhang X.; Guo L.; Zhang M.; Liu F.; Yang Q.
发表日期	2019
ISSN	1027-5606
起始页码	2779
结束页码	2794
卷号	23 期号:6
英文摘要	As a tide propagates into the estuary, river discharge affects tidal damping, primarily via a friction term, attenuating tidal motion by increasing the quadratic velocity in the numerator, while reducing the effective friction by increasing the water depth in the denominator. For the first time, we demonstrate a third effect of river discharge that may lead to the weakening of the channel convergence (i.e. landward reduction of channel width and/or depth). In this study, monthly averaged tidal water levels (2003-2014) at six gauging stations along the Yangtze River estuary are used to understand the seasonal behaviour of tidal damping and residual water level slope. Observations show that there is a critical value of river discharge, beyond which the tidal damping is reduced with increasing river discharge. This phenomenon is clearly observed in the upstream part of the Yangtze River estuary (between the Maanshan and Wuhu reaches), which suggests an important cumulative effect of residual water level on tide-river dynamics. To understand the underlying mechanism, an analytical model has been used to quantify the seasonal behaviour of tide-river dynamics and the corresponding residual water level slope under various external forcing conditions. It is shown that a critical position along the estuary is where there is maximum tidal damping (approximately corresponding to a maximum residual water level slope), upstream of which tidal damping is reduced in the landward direction. Moreover, contrary to the common assumption that larger river discharge leads to heavier damping, we demonstrate that beyond a critical value tidal damping is slightly reduced with increasing river discharge, owing to the cumulative effect of the residual water level on the effective friction and channel convergence. Our contribution describes the seasonal patterns of tide-river dynamics in detail, which will, hopefully, enhance our understanding of the nonlinear tide-river interplay and guide effective and sustainable water management in the Yangtze River estuary and other estuaries with substantial freshwater discharge. © 2019. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	Damping; Estuaries; Friction; Water conservation; Water levels; Water management; Critical positions; Cumulative effects; Freshwater discharge; Gauging stations; Quadratic velocity; Seasonal patterns; Sustainable water management; Yangtze River estuary; Rivers; convergence; damping; river discharge; seasonal variation; sustainable development; tidal cycle; water depth; water level; water management; Anhui; China; Maanshan; Wuhu; Yangtze Estuary
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159656
作者单位	Cai, H., Inst. of Estuarine and Coast. Res./State and Loc. Jt. Eng. Lab. of Estuarine Hydraulic Technology, School of Marine Engineering and Technology, Sun Yat-sen University, Guangzhou, China, Guangdong Provincial Engineering Research Center of Coasts, Islands and Reefs, Guangzhou, China, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China, State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China; Savenije, H.H.G., Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands; Garel, E., Centre for Marine and Environmental Research (CIMA), University of Algarve, Portugal; Zhang, X., Inst. of Estuarine and Coast. Res./State and Loc. Jt. Eng. Lab. of Estuarine Hydraulic Technology, School of Marine Engineering and Technology, Sun Yat-sen University, Guangzhou, China, Guangdong Provincial Engineering Research Center of Coasts, Islands and Reefs, Guangzhou, China, ...
推荐引用方式 GB/T 7714	Cai H.,Savenije H.H.G.,Garel E.,et al. Seasonal behaviour of tidal damping and residual water level slope in the Yangtze River estuary: Identifying the critical position and river discharge for maximum tidal damping[J],2019,23(6).
APA	Cai H..,Savenije H.H.G..,Garel E..,Zhang X..,Guo L..,...&Yang Q..(2019).Seasonal behaviour of tidal damping and residual water level slope in the Yangtze River estuary: Identifying the critical position and river discharge for maximum tidal damping.Hydrology and Earth System Sciences,23(6).
MLA	Cai H.,et al."Seasonal behaviour of tidal damping and residual water level slope in the Yangtze River estuary: Identifying the critical position and river discharge for maximum tidal damping".Hydrology and Earth System Sciences 23.6(2019).