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On the role of geometry of cross-section in generating flood-dominance in shallow estuaries

DRS at CSIR-National Institute of Oceanography

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Title On the role of geometry of cross-section in generating flood-dominance in shallow estuaries
 
Creator Shetye, S.R.
Gouveia, A.D.
 
Subject tidal flow
estuarine dynamics
geomorphology
ebb currents
flood currents
tidal propagation
simulation
mathematical models
 
Description Shallow estuaries often show tidal asymmetry of flood-dominance in which duration of the flood is shorter and its peak discharge larger than the corresponding values during ebb. A simple analytic model for this phenomenon is proposed. Noting that in tidal propagation in shallow, narrow estuaries, the dominant terms in the momentum balance are pressure gradient and friction, only these two terms are preserved in the model and linearize the friction. The resulting governing equation for tidal propagation is a diffusion equation with the diffusion coefficient a function of the area and the wetted perimeter of the channel cross-section. The nature of variation of both the area and the perimeter with tidal height depends on the channel geometry, and for most channels the former is more important. Solutions derived using a perturbation expansion scheme for channels with simple geometries, show that the variation of the diffusion coefficient over a tidal cycle leads to flood-dominance. This and other characteristics of the solution compare favourably with the features seen in observations
 
Date 2009-05-08T12:17:51Z
2009-05-08T12:17:51Z
1992
 
Type Journal Article
 
Identifier Estuarine, Coastal and Shelf Science, Vol.35; 113-126p.
http://drs.nio.org/drs/handle/2264/3147
 
Language en
 
Rights Copyright [1992]. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository.
 
Publisher Academic Press