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How long are tidal channels?

Published online by Cambridge University Press:  23 November 2009

G. SEMINARA
Affiliation:
Department of Civil and Environmental Engineering, University of Genova, via Montallegro 1, 16145 Genova, Italy
S. LANZONI
Affiliation:
Dipartimento di Ingegneria Idraulica, Marittima, Ambientale e Geotecnica, University of Padova, via Loredan 20, 35131 Padova, Italy
N. TAMBRONI*
Affiliation:
Department of Civil and Environmental Engineering, University of Genova, via Montallegro 1, 16145 Genova, Italy
M. TOFFOLON
Affiliation:
Department of Civil and Environmental Engineering, University of Trento, via Mesiano 77, 38100 Trento, Italy
*
Email address for correspondence: [email protected]

Abstract

Do tidal channels have a characteristic length? Given the sediment characteristics, the inlet conditions and the degree of channel convergence, can we predict it? And how is this length affected by the presence of tidal flats adjacent to the channel? We answer the above questions on the basis of a fully analytical treatment, appropriate for the short channels typically observed in coastal wetlands. The equilibrium length of non-convergent tidal channels is found to be proportional to the critical flow speed for channel erosion. Channel convergence causes concavity of the bed profile. Tidal flats shorten equilibrium channels significantly. Laboratory and field observations substantiate our findings.

Type
Papers
Copyright
Copyright © Cambridge University Press 2009

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