Frictional interactions between tidal constituents in tide-dominated estuaries

Huayang Cai, Marco Toffolon, Hubert H.G. Savenije, Qingshu Yang, Erwan Garel*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

12 Citations (Scopus)
38 Downloads (Pure)


When different tidal constituents propagate along an estuary, they interact because of the presence of nonlinear terms in the hydrodynamic equations. In particular, due to the quadratic velocity in the friction term, the effective friction experienced by both the predominant and the minor tidal constituents is enhanced. We explore the underlying mechanism with a simple conceptual model by utilizing Chebyshev polynomials, enabling the effect of the velocities of the tidal constituents to be summed in the friction term and, hence, the linearized hydrodynamic equations to be solved analytically in a closed form. An analytical model is adopted for each single tidal constituent with a correction factor to adjust the linearized friction term, accounting for the mutual interactions between the different tidal constituents by means of an iterative procedure. The proposed method is applied to the Guadiana (southern Portugal-Spain border) and Guadalquivir (Spain) estuaries for different tidal constituents (M2, S2, N2, O1, K1) imposed independently at the estuary mouth. The analytical results appear to agree very well with the observed tidal amplitudes and phases of the different tidal constituents. The proposed method could be applicable to other alluvial estuaries with a small tidal amplitude-to-depth ratio and negligible river discharge.

Original languageEnglish
Pages (from-to)769-782
Number of pages14
JournalOcean Science
Issue number4
Publication statusPublished - 8 Aug 2018


Dive into the research topics of 'Frictional interactions between tidal constituents in tide-dominated estuaries'. Together they form a unique fingerprint.

Cite this