Dynamic Analysis of Vegetated Water Flows
Publication: Journal of Hydrologic Engineering
Volume 21, Issue 2
Abstract
Substantial energy losses occur when water flows over vegetated ground. Vegetation enhances surface resistance and decreases flow velocity, which results in energy loss. Since the ground is considered to be permeable, both surface and subsurface water flow are simultaneously resolved. The objectives of this study are to analyze the dynamic effects of vegetated flows including the distributions of velocity, shear stress, and energy by an analytical approach for better understanding the physical mechanism. An inflection point in the velocity distribution is found as that in conventional research for denser vegetation cases with a constant water depth. A new dimensionless parameter, , related to permeability of porous medium and clearly affecting the shear stress distribution is proposed. The value of approximately equals 9.5 as the ratio of the water layer depth to the vegetation layer height is unity, then the shear stresses at the interface of water/vegetation layers and at the ground surface appear equivalent and reach a maximum. The results also reveal that most of the energy loss occurs near the interface of water/vegetation layers.
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Acknowledgments
This study was financially supported by the National Science Council of Taiwan, R.O.C. under grant NSC 98-2313-B-005-003-MY3. In the meanwhile, the writer wishes to thank Susan Bolton, professor, College of Forest Resources, Univ. of Washington, Seattle, WA 98195, for her helpful improvement of the writing.
References
Biot, M. A. (1956a). “Theory of propagation elastic waves in a fluid saturated porous solid. I. Low-frequency range.” J. Acoust. Soc. Am., 28(2), 168–178.
Biot, M. A. (1956b). “Theory of propagation elastic waves in a fluid saturated porous solid. II. High-frequency range.” J. Acoust. Soc. Am., 28(2), 179–191.
Chen, S. C., Kuo, Y. M., and Li, Y. H. (2011). “Flow characteristics within different configuration of submerged flexible vegetation.” J. Hydrol., 398(1–2), 124–134.
Chen, Y. C., and Kao, S. P. (2011). “Velocity distribution in open channels with submerged aquatic plant.” Hydrol. Processes, 25(13), 2009–2017.
Chow, V. T. (1973). Open-channel hydraulics, McGraw-Hill, Singapore, 149.
Flora, C., and Kroeger, R. (2014). “Use of vegetated drainage ditches and low-grade weirs for aquaculture effluent mitigation: II. Suspended sediment.” Aquacult. Eng., 60, 68–72.
Ghisalberti, M., and Nepf, H. M. (2002). “Mixing layers and coherent structures in vegetated aquatic flows.” J. Geophys. Res., 107(C2), 3-1–3-11.
Green, J. C. (2005). “Modelling flow resistance in vegetated streams: review and development of new theory.” Hydrol. Processes, 19(6), 1245–1259.
Hsieh, P. C., and Bolton, S. (2007). “Laminar surface water flow over vegetated ground.” J. Hydraul. Eng., 335–341.
Hsieh, P. C., and Shiu, Y. S. (2006). “Analytical solutions for water flow passing over a vegetal area.” Adv. Water Res., 29(9), 1257–1266.
Hsieh, P. C., Yang, J. S., and Chen, Y. C. (2012). “An integrated solution of the overland and subsurface flow along a sloping soil layer.” J. Hydrol., 460–461, 136–142.
Huai, W. X., Chen, Z. B., and Han, J. (2009a). “Mathematical model for the flow with submerged and emerged rigid vegetation.” J. Hydrodyn., 21(5), 722–729.
Huai, W. X., Han, J., Geng, C., Zhou, J. F., and Zeng, Y. H. (2009b). “Mathematical model for the flow with submerged and emerged rigid vegetation.” J. Hydrodyn., 21(5), 722–729.
Huai, W. X., Han, J., Geng, C., Zhou, J. F., and Zeng, Y. H. (2010). “The mechanism of energy loss and transition in a flow with submerged vegetation.” Adv. Water Res., 33(6), 635–639.
Hunt, S., Temple, D. M., Hanson, G. J., and Tejral, R. D. (2007). “Evolution of vegetated waterways design.” ASABE Annual Int. Meeting, USDA, Minneapolis.
Järvelä, J. (2002). “Flow resistance of flexible and stiff vegetation: a flume study with natural plants.” J. Hydrol., 269(1–2), 44–54.
Kadlec, R. H. (1990). “Overland flow in wetlands: vegetation resistance.” J. Hydraul. Eng., 691–706.
Kaviany, M. (1991). Principles of heat transfer in porous media, Springer, Berlin.
Kouwen, N., Li, R. M., and Simons, D. B. (1981). “Flow resistance in vegetated waterways.” Trans. ASCE, 24(3), 684–698.
Kouwen, N., and Unny, T. E. (1973). “Flexible roughness in open channels.” J. Hydraul. Div., 99(HY5), 713–728.
Kubrak, E., Kubrak, J., and Rowiński, P. M. (2008). “Vertical velocity distributions through and above submerged, flexible vegetation.” J. Hydrol. Sci., 53(4), 905–920.
Kutija, V., and Hong, H. T. M. (1996). “A numerical model for assessing the additional resistance to flow introduced by flexible vegetation.” J. Hydraul. Res., 34(1), 99–114.
Nepf, H. M., and Vivoni, E. R. (2000). “Flow structure in depth-limited, vegetated flow.” J. Geophys. Res., 105(C12), 28547–28557.
Palmer, V. J. (1945). “A method for designing vegetated waterways.” Agric. Eng., 26(12), 516–520.
Ree, W. O., and Crow, F. R. (1977). “Friction factors for vegetated waterways of small slope.” ARSS-151, Agricultural Research Service, U.S. Dept. of Agriculture, Washington, DC, 1–56.
Watanabe, T., and Kondo, J. (1990). “The influence of canopy structure and density upon the mixing length within and above vegetation.” J. Meteorol. Soc. Jpn., 68(2), 227–235.
Wu, F. C., Shen, H. W., and Chou, Y. J. (1999). “Variation of roughness coefficients for unsubmerged and submerged vegetation.” J. Hydraul. Eng., 934–942.
Wu, F. S. (2008). “Characteristics of flow resistance in open channels with non-submerged rigid vegetation.” J. Hydrodyn., 20(2), 239–245.
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Published In
Journal of Hydrologic Engineering
Volume 21 • Issue 2 • February 2016
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Mar 25, 2015
Accepted: Jul 20, 2015
Published online: Sep 18, 2015
Published in print: Feb 1, 2016
Discussion open until: Feb 18, 2016
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