Leaf Area Index as Vegetation Density Measure for Hydraulic Analyses
Publication: Journal of Hydraulic Engineering
Volume 139, Issue 5
Abstract
The correct parameterization of vegetation using measurable plant characteristics is essential for reliable flow resistance estimates. This paper focuses on the impact of density and distribution of the leaf mass on the drag force. Direct drag force measurements on flexible artificial plants were conducted in a stand. The experiments were novel in that the leaf area index (LAI) was varied in two ways: (1) the distances between the plants were altered, and (2) the leaf area of the plants was doubled and tripled. In addition, the vertical leaf area distribution was examined. The drag forces depended on the leaf mass in a similar fashion regardless of the horizontal distribution of the leaf mass, but the vertical distribution had a more significant impact. Shading of the leaves slightly reduced resistance for bushy plants because the leaf mass hidden behind the frontal projected area exerted drag. The experiments confirmed LAI to be a useful measure in estimating vegetative resistance.
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Acknowledgments
This research was supported by the Academy of Finland, Maa-ja vesitekniikan tuki ry., and Deutsche Forschungsgemeinschaft (AB 137/3).
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Information & Authors
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Published In
Journal of Hydraulic Engineering
Volume 139 • Issue 5 • May 2013
Pages: 461 - 469
Copyright
© 2013 American Society of Civil Engineers.
History
Received: May 30, 2012
Accepted: Nov 6, 2012
Published online: Nov 8, 2012
Published in print: May 1, 2013
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