Experimental Investigation of Wave Attenuation through Model and Live Vegetation
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 140, Issue 5
Abstract
Wetland vegetation can attenuate storm surge and waves and thus play an important role in coastal protection. In this study, laboratory experiments were used to quantify wave attenuation as a function of vegetation type, density, and height, as well as wave conditions. Wave attenuation characteristics were investigated under regular and irregular waves for rigid and flexible model vegetation in addition to live Spartina alterniflora and Juncus roemerianus, two common coastal species. Vegetation densities were for model vegetation, for S. alterniflora, and for J. roemerianus. Bulk drag coefficients () of the vegetation species were calibrated based on wave gauge data and video images, and regression equations were derived for the drag coefficient as a function of Keulegan-Carpenter number (). did not depend significantly on the relative vegetation height with respect to water depth for rigid vegetation models in the emergent and submerged conditions tested here. In general, drag coefficients were higher for live vegetation species than for rigid and flexible vegetation models. The results also showed that vertical variation of plant density strongly influenced the drag coefficient.
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Acknowledgments
This research was supported by the U.S. Department of Homeland Security–sponsored Southeast Region Research Initiative (SERRI) at the U.S. DOE’s Oak Ridge National Laboratory, and in part by the ARS under Specific Research Agreement No. 58-6408-1-609 monitored by the USDA-ARS National Sedimentation Laboratory and the University of Mississippi. Glenn Gray and Jeffrey Diers are recognized for their efforts in flume construction and preparation. This work is dedicated to the memory of Kevser Ermin.
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Published In
Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 140 • Issue 5 • September 2014
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Jul 10, 2012
Accepted: Dec 6, 2013
Published online: Dec 9, 2013
Discussion open until: Aug 7, 2014
Published in print: Sep 1, 2014
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