Abstract
Hydraulic models used to simulate floods through riparian forests along rivers need to account for flow resistance caused by tree drag. Tree drag formulations have been developed for this purpose in previous studies, using drag force measurements on several broad-leaved, temperate species at tree scale to calibrate model parameters. However, tree reconfiguration and reduction in drag force in response to increased flow velocity are still not fully understood, particularly for subtropical tree species with sclerophyllous foliage. An established towing tank method was adapted to a field setting using a motorboat to tow submerged she-oak and tea trees through still water. Drag coefficients for both genera decreased with increasing velocity due to stem and foliage reconfiguration, except for the lowest velocity measurements on some she-oak trees, indicating the emergence of a rigid regime. The rigid regime has also been observed in previous studies and is important for flood modeling because drag forces could otherwise be overestimated at low velocities. Therefore, a new Cauchy number has been formulated and tested to predict regime transition for she-oak trees.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code generated or used during the study are available in a repository or online in accordance with funder data retention policies (Sharpe 2021).
Acknowledgments
Financial support for this work was provided through a postgraduate scholarship awarded by Griffith University to the lead author. The drag resistance frame was fabricated by John Wedmaier at the Griffith University mechanical workshop. The authors are grateful for the assistance provided by Lawrence Hughes, who piloted the boat, managed all boat arrangements, and collected the ADCP data. We thank Seqwater for granting us access to Hinze Dam and two anonymous reviewers whose thoughtful suggestions helped to improve the manuscript.
References
Aberle, J., and J. Järvelä. 2013. “Flow resistance of emergent rigid and flexible floodplain vegetation.” J. Hydraul. Res. 51 (1): 33–45. https://doi.org/10.1080/00221686.2012.754795.
Antonarakis, A. S., K. S. Richards, J. Brasington, and E. Muller. 2010. “Determining leaf area index and leafy tree roughness using terrestrial laser scanning.” Water Resour. Res. 46 (6): W06510. https://doi.org/10.1029/2009WR008318.
Armanini, A., M. Righetti, and P. Grisenti. 2005. “Direct measurement of vegetation resistance in prototype scale.” J. Hydraul. Res. 43 (5): 481–487. https://doi.org/10.1080/00221680509500146.
Baptist, M., V. Babovic, J. Rodríguez Uthurburu, M. Keijzer, R. Uittenbogaard, A. Mynett, and A. Verwey. 2007. “On inducing equations for vegetation resistance.” J. Hydraul. Res. 45 (4): 435–450. https://doi.org/10.1080/00221686.2007.9521778.
Ben Meftah, M., and M. Mossa. 2013. “Prediction of channel flow characteristics through square arrays of emergent cylinders.” Phys. Fluids 25 (4): 045102. https://doi.org/10.1063/1.4802047.
Chen, L., K. Acharya, and M. C. Stone. 2014. “Using a mechanical approach to quantify flow resistance by submerged, flexible vegetation—A revisit of Kouwen’s approach.” Adv. Water Resour. 73 (Nov): 198–202. https://doi.org/10.1016/j.advwatres.2014.08.014.
Chen, L., and X. Chen. 2017. “Comments on ‘An improved Cauchy number approach for predicting the drag and reconfiguration of flexible vegetation’ by Peter Whittaker, Catherine A.M.E. Wilson, and Jochen Aberle.” Adv. Water Resour. 105: 233–235. https://doi.org/10.1016/j.advwatres.2016.10.017.
Cheng, N.-S. 2011. “Representative roughness height of submerged vegetation.” Water Resour. Res. 47 (8): 124–134. https://doi.org/10.1029/2011WR010590.
Chow, V. T. 1959. Open channel hydraulics. New York: McGraw-Hill.
Dalledonne, G. L., R. Kopmann, and T. Brudy-Zippelius. 2019. “Uncertainty quantification of floodplain friction in hydrodynamic models.” Hydrol. Earth Syst. Sci. 23 (8): 3373–3385. https://doi.org/10.5194/hess-23-3373-2019.
De Langre, E. 2008. “Effects of wind on plants.” Annu. Rev. Fluid Mech. 40: 141–168. https://doi.org/10.1146/annurev.fluid.40.111406.102135.
Erskine, W., A. Chalmers, A. Keene, M. Cheetham, and R. Bush. 2009. “Role of a rheophyte in bench development on a sand-bed river in southeast Australia.” Earth Surf. Processes Landforms 34 (7): 941–953. https://doi.org/10.1002/esp.1778.
Fathi-Maghadam, M., and N. Kouwen. 1997. “Nonrigid, nonsubmerged, vegetative roughness on floodplains.” J. Hydraul. Eng. 123 (1): 51–57. https://doi.org/10.1061/(ASCE)0733-9429(1997)123:1(51).
Gosselin, F., E. de Langre, and B. A. Machado-Almeida. 2010. “Drag reduction of flexible plates by reconfiguration.” J. Fluid Mech. 650: 319–341. https://doi.org/10.1017/S0022112009993673.
Guillén-Ludeña, S., D. Lopez, E. Mignot, and N. Riviere. 2020. “Flow resistance for a varying density of obstacles on smooth and rough beds.” J. Hydraul. Eng. 146 (2): 04019059. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001676.
Hassani, M., N. W. Mureithi, and F. P. Gosselin. 2016. “Large coupled bending and torsional deformation of an elastic rod subjected to fluid flow.” J. Fluids Struct. 62: 367–383. https://doi.org/10.1016/j.jfluidstructs.2015.12.009.
Huthoff, F., D. C. M. Augustijn, and S. J. M. H. Hulscher. 2007. “Analytical solution of the depth-averaged flow velocity in case of submerged rigid cylindrical vegetation.” Water Resour. Res. 43 (6): W06413. https://doi.org/10.1029/2006WR005625.
Jalonen, J., and J. Järvelä. 2014. “Estimation of drag forces caused by natural woody vegetation of different scales.” J. Hydrodyn. 26 (4): 608–623. https://doi.org/10.1016/S1001-6058(14)60068-8.
James, C. S., A. L. Birkhead, A. A. Jordanova, and J. J. O’Sullivan. 2004. “Flow resistance of emergent vegetation.” J. Hydraul. Res. 42 (4): 390–398. https://doi.org/10.1080/00221686.2004.9728404.
Järvelä, J. 2004. “Determination of flow resistance caused by non-submerged woody vegetation.” Int. J. River Basin Manage. 2 (1): 61–70. https://doi.org/10.1080/15715124.2004.9635222.
Klopstra, D., H. Barneveld, J. Van Noortwijk, and E. Van Velzen. 1997. “Analytical model for hydraulic roughness of submerged vegetation.” In Proc., 27th IAHR World Congress, 775–780. Madrid, Spain: International Association for Hydro-Environment Engineering and Research.
Leclercq, T., and E. De Langre. 2016. “Drag reduction by elastic reconfiguration of non-uniform beams in non-uniform flows.” J. Fluids Struct. 60: 114–129. https://doi.org/10.1016/j.jfluidstructs.2015.10.007.
Li, R.-M., and H. W. Shen. 1973. “Effect of tall vegetations on flow and sediment.” J. Hydraul. Div. 99 (5): 793–814. https://doi.org/10.1061/JYCEAJ.0003647.
López, F., and M. H. García. 2001. “Mean flow and turbulence structure of open-channel flow through non-emergent vegetation.” J. Hydraul. Eng. 127 (5): 392–402. https://doi.org/10.1061/(ASCE)0733-9429(2001)127:5(392).
Luhar, M., and H. M. Nepf. 2011. “Flow-induced reconfiguration of buoyant and flexible aquatic vegetation.” Limnol. Oceanogr. 56 (6): 2003–2017. https://doi.org/10.4319/lo.2011.56.6.2003.
Luhar, M., and H. M. Nepf. 2013. “From the blade scale to the reach scale: A characterization of aquatic vegetative drag.” Adv. Water Resour. 51: 305–316. https://doi.org/10.1016/j.advwatres.2012.02.002.
Marjoribanks, T. I., R. J. Hardy, S. N. Lane, and D. R. Parsons. 2014. “High-resolution numerical modelling of flow–vegetation interactions.” J. Hydraul. Res. 52 (6): 775–793. https://doi.org/10.1080/00221686.2014.948502.
Nakayama, Y. 2018. Introduction to fluid mechanics. 2nd ed. Oxford, UK: Butterworth-Heinemann.
Oplatka, M. 1998. “Stabilität von weidenverbauungen an flussufern.” Ph.D. dissertation, ETH Zürich. http://hdl.handle.net/20.500.11850/143576.
Petryk, S., and G. Bosmajian III. 1975. “Analysis of flow through vegetation.” J. Hydraul. Div. 101 (7): 871–884. https://doi.org/10.1061/JYCEAJ.0004397.
Schlichting, H., and K. Gersten. 2016. Boundary-layer theory. New York: Springer.
Sharpe, R., A. Brooks, J. Olley, L. Hughes, and J. Kemp. 2019. “Measuring drag forces on Casuarina cunninghamiana in experimental and field settings.” In Proc., 38th IAHR World Congress. Madrid, Spain: International Association for Hydro-Environment Engineering and Research.
Sharpe, R. G. 2021. “Drag on submerged trees.” Accessed January 9, 2021. http://osf.io/kp4qv.
Stone, M. C., L. Chen, S. Kyle McKay, J. Goreham, K. Acharya, C. Fischenich, and A. B. Stone. 2013. “Bending of submerged woody riparian vegetation as a function of hydraulic flow conditions.” River Res. Appl. 29 (2): 195–205. https://doi.org/10.1002/rra.1592.
Tanaka, N., and J. Yagisawa. 2009. “Effects of tree characteristics and substrate condition on critical breaking moment of trees due to heavy flooding.” Landscape Ecol. Eng. 5 (1): 59–70. https://doi.org/10.1007/s11355-008-0060-5.
Västilä, K., and J. Järvelä. 2014. “Modeling the flow resistance of woody vegetation using physically based properties of the foliage and stem.” Water Resour. Res. 50 (1): 229–245. https://doi.org/10.1002/2013WR013819.
Västilä, K., J. Järvelä, and J. Aberle. 2013. “Characteristic reference areas for estimating flow resistance of natural foliated vegetation.” J. Hydrol. 492 (Jun): 49–60. https://doi.org/10.1016/j.jhydrol.2013.04.015.
Vogel, S. 1984. “Drag and flexibility in sessile organisms.” Am. Zool. 24 (1): 37–44. https://doi.org/10.1093/icb/24.1.37.
Vollsinger, S., S. J. Mitchell, K. E. Byrne, M. D. Novak, and M. Rudnicki. 2005. “Wind tunnel measurements of crown streamlining and drag relationships for several hardwood species.” Can. J. For. Res. 35 (5): 1238–1249. https://doi.org/10.1139/x05-051.
Wang, J., and Z. Zhang. 2019. “Evaluating riparian vegetation roughness computation methods integrated within HEC-RAS.” J. Hydraul. Eng. 145 (6): 04019020. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001597.
Wheeler, G. S., G. S. Taylor, J. Gaskin, and M. F. Purcell. 2011. “Ecology and management of Sheoak (Casuarina spp.), an invader of coastal Florida, USA.” J. Coastal Res. 27 (3): 485–492. https://doi.org/10.2112/JCOASTRES-D-09-00110.1.
Whittaker, P., C. Wilson, J. Aberle, H. P. Rauch, and P. Xavier. 2013. “A drag force model to incorporate the reconfiguration of full-scale riparian trees under hydrodynamic loading.” J. Hydraul. Res. 51 (5): 569–580. https://doi.org/10.1080/00221686.2013.822936.
Whittaker, P., C. A. M. E. Wilson, and J. Aberle. 2015. “An improved Cauchy number approach for predicting the drag and reconfiguration of flexible vegetation.” Adv. Water Resour. 83 (Sep): 28–35. https://doi.org/10.1016/j.advwatres.2015.05.005.
Wilson, C. A., J. Hoyt, and I. Schnauder. 2008. “Impact of foliage on the drag force of vegetation in aquatic flows.” J. Hydraul. Eng. 134 (7): 885–891. https://doi.org/10.1061/(ASCE)0733-9429(2008)134:7(885).
Woolfrey, A., and P. Ladd. 2001. “Habitat preference and reproductive traits of a major Australian riparian tree species (Casuarina cunninghamiana).” Aust. J. Bot. 49 (6): 705–715. https://doi.org/10.1071/BT01009.
Wu, F.-C., H. W. Shen, and Y.-J. Chou. 1999. “Variation of roughness coefficients for unsubmerged and submerged vegetation.” J. Hydraul. Eng. 125 (9): 934–942. https://doi.org/10.1061/(ASCE)0733-9429(1999)125:9(934).
Wunder, S., B. Lehmann, and F. Nestmann. 2011. “Determination of the drag coefficients of emergent and just submerged willows.” Int. J. River Basin Manage. 9 (3–4): 231–236. https://doi.org/10.1080/15715124.2011.637499.
Xavier, P. A. 2009. “Floodplain woodland hydrodynamics.” Ph.D. dissertation, Cardiff School of Engineering, Div. of Civil and Structural Engineering, Cardiff Univ.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 147 • Issue 10 • October 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Feb 3, 2021
Accepted: Jun 9, 2021
Published online: Aug 14, 2021
Published in print: Oct 1, 2021
Discussion open until: Jan 14, 2022
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.
Cited by
- Richard Gordon Sharpe, Andrew Brooks, Jon Olley, Justine Kemp, Quantifying hydraulic roughness in a riparian forest using a drag force‐based method, Journal of Flood Risk Management, 10.1111/jfr3.12892, (2023).
- Walter Box, Juha Järvelä, Kaisa Västilä, New formulas addressing flow resistance of floodplain vegetation from emergent to submerged conditions, International Journal of River Basin Management, 10.1080/15715124.2022.2143512, (1-17), (2022).