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Effect of river discharge and geometry on tides and net water transport in an estuarine network, an idealized model applied to the Yangtze Estuary
- Source :
- Continental Shelf Research, 123, 29. Elsevier Limited
- Publication Year :
- 2016
-
Abstract
- Tidal propagation in, and division of net water transport over different channels in an estuarine network are analyzed using a newly developed idealized model. The water motion in this model is governed by the cross-sectionally averaged shallow water equations and is forced by tides at the seaward boundaries and by river discharge. Approximate analytical solutions are constructed by means of a harmonic truncation and a perturbation expansion in a small parameter, being the ratio of tidal amplitude and depth. The net water transport results from an imposed river discharge and from residual water transport generated by nonlinear tidal rectification. Two new drivers are identified that contribute to the net water transport in tidal estuarine networks, viz. the generation of residual water transport due to gradients in dynamic pressure and due to a coupling between the tidally averaged and quarter diurnal currents through the quadratic bottom stress. The model is applied in a case study on the Yangtze Estuary, to investigate tides and division of net water transport over its multiple channels during the wet and dry season, as well as before and after the construction of the Deepwater Navigation Channel. Model results agree fairly well with observations. Process analysis reveals that the decrease in tides from dry to wet season is due to enhanced bottom stress generated by river-tide interactions. Also, the seasonal variations in net water transport are explained. It is furthermore shown and explained that due to the Deepwater Navigation Channel tidal currents have increased and net water transport has decreased in the North Passage. These changes have profound implications for net sediment transport and salinity intrusion.
- Subjects :
- 010504 meteorology & atmospheric sciences
0208 environmental biotechnology
02 engineering and technology
Aquatic Science
Oceanography
01 natural sciences
Physics::Geophysics
River-tide interactions
Estuarine water circulation
Taverne
Shallow water equations
Physics::Atmospheric and Oceanic Physics
0105 earth and related environmental sciences
Hydrology
geography
Water transport
geography.geographical_feature_category
Discharge
Tidal irrigation
Tidal rectification
Estuary
Geology
Seasonal variability
020801 environmental engineering
Salinity
Friction linearization
Environmental science
Astrophysics::Earth and Planetary Astrophysics
Chebyshev polynomials
Sediment transport
Subjects
Details
- Language :
- English
- ISSN :
- 02784343
- Volume :
- 123
- Database :
- OpenAIRE
- Journal :
- Continental Shelf Research
- Accession number :
- edsair.doi.dedup.....f05c39394835bc169dddc2e483d55abb