Representative roughness height of submerged vegetation
Date of Issue2011
School of Civil and Environmental Engineering
Roughness length scale is important in the evaluation of resistance caused by submerged vegetation in open channel flows. By transforming the concept of hydraulic radius, a representative roughness height is proposed in this study for quantifying effect of submerged vegetation on flow resistance in the surface layer. The proposed roughness height is characterized by its proportionality to both stem diameter and vegetation concentration and performs better than other length scales in collapsing resistance data collected under a wide range of vegetation conditions. An approach is then developed for estimate of the average flow velocity and thus resistance coefficients for both cases of rigid and flexible vegetation. Comparisons are also made between the present study and other four formulas available in the literature. This study also shows that all the formulas, if simplified for some simple conditions, can be unified in a general form.
DRNTU::Engineering::Civil engineering::Water resources
Water resources research
© 2011 American Geophysical Union. This paper was published in Water Resources Research and is made available as an electronic reprint (preprint) with permission of American Geophysical Union. The paper can be found at: [DOI: http://dx.doi.org/10.1029/2011WR010590]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.