Frictional interactions between tidal constituents in tide-dominated estuaries
<p>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 mino...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-08-01
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| Series: | Ocean Science |
| Online Access: | https://www.ocean-sci.net/14/769/2018/os-14-769-2018.pdf |
| Summary: | <p>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 (<i>M</i><sub>2</sub>, <i>S</i><sub>2</sub>, <i>N</i><sub>2</sub>, <i>O</i><sub>1</sub>, <i>K</i><sub>1</sub>)
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.</p> |
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| ISSN: | 1812-0784 1812-0792 |