Sediment patterns near a model patch of reedy emergent vegetation



Follett, Elizabeth M ORCID: 0000-0001-9993-5313 and Nepf, Heidi M
(2012) Sediment patterns near a model patch of reedy emergent vegetation. GEOMORPHOLOGY, 179. pp. 141-151.

Access the full-text of this item by clicking on the Open Access link.

Abstract

This laboratory study describes the sediment patterns formed in a sand bed around circular patches of rigid vertical cylinders, representing a patch of reedy emergent vegetation. The patch diameter was much smaller than the channel width. Two patch densities (solid volume fraction 3% and 10%) and two patch diameters (22 and 10. cm) were considered. For flows above the threshold of sediment motion, patterns of sediment erosion and deposition were observed around and within the patch. Scouring within the patch was positively correlated with turbulent kinetic energy in the patch. For sparse patches, sediment scoured from within the patch was mostly deposited within one patch diameter downstream of the patch. For dense patches, which experience greater flow diversion, sediment scoured from the patch was carried farther downstream before deposition along the patch centerline. Differences between the sparse and dense patch patterns of deposition are explained in the context of flow diversion and wake structure, which are related to a nondimensional flow blockage parameter. While sediment was redistributed near the patch, observations suggest that net deposition was not recorded at the reach scale. © 2012 Elsevier B.V.

Item Type: Article
Uncontrolled Keywords: Emergent vegetation, Sediment transport, Wake, Deposition, Flume, Porous patch
Divisions: Faculty of Science and Engineering > School of Engineering
Depositing User: Symplectic Admin
Date Deposited: 06 Jan 2023 11:09
Last Modified: 06 Jan 2023 11:09
DOI: 10.1016/j.geomorph.2012.08.006
Open Access URL: https://dspace.mit.edu/handle/1721.1/99230
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3166854