A vortex-based model of velocity and shear stress in a partially vegetated shallow channel
MetadataShow full item record
This paper presents a method for predicting the distributions of velocity and shear stress in shallow channels with a boundary of emergent vegetation. Experiments in a laboratory channel with model vegetation show that the velocity profile exhibits a distinct two-layer structure, consisting of a rapidly varying shear layer across the vegetation interface and a more gradual boundary layer in the main channel. In addition, coherent vortices are observed which span both layers, and are the dominant contributors to lateral momentum fluxes. From these observations, we propose a model for the vortex-induced exchange and find expressions for the width of momentum penetration into the vegetation, the velocity and shear stress at the vegetation edge, and the width of the boundary layer in the main channel. These variables, along with a momentum balance in the main channel, comprise a modeling framework which accurately reproduces the observed velocity and shear stress distributions. The predictions for the velocity and shear stress can provide a basis for modeling flood conveyance, overbank sediment transport, and scalar residence time in the vegetated layer.
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Water Resources Research 44 (2008): W01412, doi:10.1029/2006WR005651.
Showing items related by title, author, creator and subject.
Friedrichs, Carl T. (Woods Hole Oceanographic Institution, 1993-02)In this thesis, mechanisms which control morphodynamics of shallow tidal embayments are investigated analytically. In the process of exploring these mechanisms (specifically asymmetries in bottom stress, τ), basis momentum ...
Relative sea-level rise and the development of channel-fill and shallow-water sequences on Cape Cod, Massachusetts Gutierrez, Benjamin T. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1999-01)Channel-fill sediments located in shallow-water off the south shore of Cape Cod, Massachusetts, provide a record of the late-Pleistocene and Holocene geological evolution in a post-glacial setting. Though conventionally ...
Buck, John R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1996-06)The shallow water acoustic channel supports far-field propagation in a discrete set of modes. Ocean experiments have confirmed the modal nature of acoustic propagation, but no experiment has successfully excited only one ...