Sediment patterns near a model patch of reedy emergent vegetation
Name
Nepf_sediment patterns.pdf
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13.81 MB
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Adobe PDF
Checksum (MD5)
6317bfff71bc87716b57a1dfab5e0587
Author(s)
Follett, Elizabeth M.
Nepf, Heidi
Date Issued
August 2012
Journal
Geomorphology
Publisher
Elsevier
Citation
Follett, Elizabeth M., and Heidi M. Nepf. “Sediment Patterns Near a Model Patch of Reedy Emergent Vegetation.” Geomorphology 179 (December 2012): 141–151.
Version
Author's final manuscript
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.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Terms of Use
Creative Commons Attribution-Noncommercial-NoDerivatives
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DOI of Published Version
https://doi.org/10.1016/j.geomorph.2012.08.006
