Flow structure in depth-limited, vegetated flow

H. M. Nepf, Enrique Vivoni

Research output: Contribution to journalArticle

450 Citations (Scopus)

Abstract

Aquatic vegetation controls the mean and turbulent flow structure in channels and coastal regions and thus impacts the fate and transport of sediment and contaminants. Experiments in an open-channel flume with model vegetation were used to better understand how vegetation impacts flow. In particular, this study describes the transition between submerged and emergent regimes based on three aspects of canopy flow: mean momentum, turbulence, and exchange dynamics. The observations suggest that flow within an aquatic canopy may be divided into two regions. In the upper canopy, called the "vertical exchange zone", vertical turbulent exchange with the overlying water is dynamically significant to the momentum balance and turbulence; and turbulence produced by mean shear at the top of the canopy is important. The lower canopy is called the "longitudinal exchange zone" because it communicates with surrounding water predominantly through longitudinal advection. In this region turbulence is generated locally by the canopy elements, and the momentum budget is a simple balance of vegetative drag and pressure gradient. In emergent canopies, only a longitudinal exchange zone is present. When the canopy becomes submerged, a vertical exchange zone appears at the top of the canopy and deepens into the canopy as the depth of submergence increases.

Original languageEnglish (US)
Article number2000JC900145
Pages (from-to)28547-28557
Number of pages11
JournalJournal of Geophysical Research: Oceans
Volume105
Issue numberC12
StatePublished - Dec 15 2000
Externally publishedYes

Fingerprint

canopies
flow structure
Flow structure
Turbulence
canopy
Momentum
vegetation
turbulence
Water
Advection
Pressure gradient
momentum
Turbulent flow
Drag
Sediments
Impurities
submergence
advection
turbulent flow
pressure gradients

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Atmospheric Science
  • Astronomy and Astrophysics
  • Oceanography

Cite this

Flow structure in depth-limited, vegetated flow. / Nepf, H. M.; Vivoni, Enrique.

In: Journal of Geophysical Research: Oceans, Vol. 105, No. C12, 2000JC900145, 15.12.2000, p. 28547-28557.

Research output: Contribution to journalArticle

Nepf, HM & Vivoni, E 2000, 'Flow structure in depth-limited, vegetated flow', Journal of Geophysical Research: Oceans, vol. 105, no. C12, 2000JC900145, pp. 28547-28557.
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