Impact of Patchy Vegetation on Tsunami Dynamics
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 143, Issue 4
Abstract
Coastal vegetation is capable of mitigating tsunami damage. Yet, the complex tsunami dynamics induced by spatial variability of onshore vegetation are not well understood at present. Laboratory and numerical investigations were conducted to study the impact of patchy vegetation on tsunami dynamics. Roughness patches composed of various cylinder numbers and spacings represented different bulk vegetative conditions in the experiments, and a Boussinesq model was applied to extend the range of the experiments. Analysis revealed that roughness patches reduced the maximum momentum flux by up to 80% over most areas, whereas within-patch roughness variation induced uncertainty on hydrodynamics adjacent to the seaward patches. Dimensional analysis revealed a logarithmic relation between the area protected from extreme momentum flux and the total roughness area. These findings demonstrate that patchy vegetation, with appropriate configuration, can be as effective as a continuous forest belt in mitigating tsunami hazards.
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Acknowledgments
This material is based on work supported by the National Science Foundation (Grant CMMI-1206271). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. The authors acknowledge Advanced Research Computing at Virginia Tech for providing computational resources and technical support that contributed to the results reported within this paper. The authors especially thank Dr. P. J. Lynett (University of Southern California) for providing the source code of COULWAVE and T. Irish for comments on editing the paper. Help from staff and students during the experiments in the Hinsdale Wave Research Laboratory at Oregon State University is gratefully acknowledged.
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Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 143 • Issue 4 • July 2017
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© 2017 American Society of Civil Engineers.
History
Received: May 25, 2016
Accepted: Oct 18, 2016
Published online: Feb 22, 2017
Published in print: Jul 1, 2017
Discussion open until: Jul 22, 2017
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