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Sensitivity of estuarine turbidity maximum to settling velocity, tidal mixing, and sediment supply

Proceedings in Marine Science

By:
, ,
Edited by:
Maa J.P.Y.Sanford L.P.Schoellhamer D.H.
DOI: 10.1016/S1568-2692(07)80022-2

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Abstract

Estuarine turbidity maximum, numerical modeling, settling velocity, stratification The spatial and temporal distribution of suspended material in an Estuarine Turbidity Maxima (ETM) is primarily controlled by particle settling velocity, tidal mixing, shear-stress thresholds for resuspension, and sediment supply. We vary these parameters in numerical experiments of an idealized two-dimensional (x-z) estuary to demonstrate their affects on the development and retention of particles in an ETM. Parameters varied are the settling velocity (0.01, 0.1, and 0.5 mm/s), tidal amplitude (0.4 m 12 hour tide and 0.3 to 0.6 m 14 day spring neap cycle), and sediment availability (spatial supply limited or unlimited; and temporal supply as a riverine pulse during spring vs. neap tide). Results identify that particles with a low settling velocity are advected out of the estuary and particles with a high settling velocity provide little material transport to an ETM. Particles with an intermediate settling velocity develop an ETM with the greatest amount of material retained. For an unlimited supply of sediment the ETM and limit of salt intrusion co-vary during the spring neap cycle. The ETM migrates landward of the salt intrusion during spring tides and seaward during neap tides. For limited sediment supply the ETM does not respond as an erodible pool of sediment that advects landward and seaward with the salt front. The ETM is maintained seaward of the salt intrusion and controlled by the locus of sediment convergence in the bed. For temporal variability of sediment supplied from a riverine pulse, the ETM traps more sediment if the pulse encounters the salt intrusion at neap tides than during spring tides. ?? 2007 Elsevier B.V. All rights reserved.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Sensitivity of estuarine turbidity maximum to settling velocity, tidal mixing, and sediment supply
Series title:
Proceedings in Marine Science
ISBN:
9780444521637
DOI:
10.1016/S1568-2692(07)80022-2
Volume
8
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Proceedings in Marine Science
First page:
355
Last page:
376
Number of Pages:
22