An Index to Determine Reaction of Vegetation Canopies to River Flow

Document Type : Original Article

Authors

Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran.

10.22044/jhwe.2023.13441.1027

Abstract

Physical properties of tree species determine their reaction to external loads as a result of water flow. The greater the trees ability to withstand water load, the greater the amount of water energy absorption, generation of water eddies, and the acceleration of turbulence in vegetation canopies. This will increase water flow energy lost. In general, physical properties of trees include leaf density, shape, and overall flexibility of their species. In this study, an index is proposed to characterize physical properties of tree species. This will enable the application of a single momentum (or energy) equation to determine overall reaction of variety of tree species in a community. The index is derived based on the resonance frequency of the first mode of vibration of trees and a fundamental relationship for the homogeneous beams. The derived indexes for four species of coniferous trees were used in a mathematical model to estimate the drag and energy coefficients as representatives for tree reaction to water flow, and could account for the differences due to the leaf density, shape, and rigidity of the tree species.

Keywords


Aberle, J., Järvelä, J., 2013. Flow resistance of emergent rigid and flexible floodplain vegetation. Journal of Hydraulic Research, 51(1): 33-45.
Chenge, I.B., 2021. Height–diameter relationship of trees in Omo strict nature forest reserve, Nigeria. Trees, Forests and People, 3: 100051.
Clough, R.W., Penzien, J., 2003. Dynamics of structures. Berkeley. CA: Computers and Structures.
Fang, Z., Gong, C., Revell, A., O’Connor, J., 2022. Fluid–structure interaction of a vegetation canopy in the mixing layer. Journal of Fluids and Structures, 109: 103467.
Fathi-Moghadam, M., Yarahmadi, M., Bajestan, M., 2010. Effects of land slope and flow depth on retarding flow in gravel-bed lands. Middle East Journal of Scientific Research, 5(6): 464-468.
Fisher, K., Dawson, H., 2003. Reducing uncertainty in river flood conveyance. Roughness review.
Freeman, G.E., Rahmeyer, W.H., Copeland, R.R., 2000. Determination of resistance due to shrubs and woody vegetation.
Gosselin, F.P., 2019. Mechanics of a plant in fluid flow. Journal of Experimental Botany, 70(14): 3533-3548.
Järvelä, J., 2002. Flow resistance of flexible and stiff vegetation: a flume study with natural plants. Journal of hydrology, 269(1-2): 44-54.
Järvelä, J., 2004. Determination of flow resistance caused by non‐submerged woody vegetation. International Journal of River Basin Management, 2(1): 61-70.
Ji, U., Järvelä, J., Västilä, K., Bae, I., 2023. Experimentation and Modeling of Reach-Scale Vegetative Flow Resistance due to Willow Patches. Journal of Hydraulic Engineering, 149(7): 04023018.
Kafuti, C. et al., 2022. Height-diameter allometric equations of an emergent tree species from The Congo Basin. Forest Ecology and Management, 504: 119822.
Kouwen, N., Fathi-Moghadam, M., 2000. Friction factors for coniferous trees along rivers. Journal of hydraulic engineering, 126(10): 732-740.
Makowski, M. et al., 2019. Synthetic silviculture: Multi-scale modeling of plant ecosystems. ACM Transactions on Graphics (TOG), 38(4): 1-14.
McMahon, T.A., Kronauer, R.E., 1976. Tree structures: deducing the principle of mechanical design. Journal of theoretical biology, 59(2): 443-466.
Mewis, P., 2021. Estimation of vegetation-induced flow resistance for hydraulic computations using airborne laser scanning data. Water, 13(13): 1864.
Moreno-Fernández, D. et al., 2018. National-scale assessment of forest site productivity in Spain. Forest Ecology and Management, 417: 197-207.
Niklas, K.J., 1992. Plant biomechanics: an engineering approach to plant form and function. University of Chicago press.
Niklas, K.J., Moon, F.C., 1988. Flexural stiffness and modulus of elasticity of flower stalks from Allium sativum as measured by multiple resonance frequency spectra. American Journal of Botany, 75(10): 1517-1525.
PUGSLEY, A., 1988. Limits to size set by trees. Structural (The) engineer. Part A: the journal of the Institution of Structural Engineers-monthly, 66(19): 322-323.
Rautiainen, M., Stenberg, P., Nilson, T., Kuusk, A., Smolander, H., 2003. Application of a forest reflectance model in estimating leaf area index of Scots pine stands using Landsat-7 ETM reflectance data. Canadian journal of remote sensing, 29(3): 314-323.
Stenberg, P., Nilson, T., Smolander, H., Voipio, P., 2003. Gap fraction based estimation of LAI in Scots pine stands subjected to experimental removal of branches and stems. Canadian Journal of Remote Sensing, 29(3): 363-370.
Timoshenko, S.P., Gere, J.M., 2009. Theory of elastic stability. Courier Corporation.
Tsujimoto, T., Kitamura, T., Okada, T., 1991. Turbulent structure of flow over rigid vegetation covered bed in open-channel KHL Progressive Report 7, Hydr. Lab., Kanazaw a University, Japan.
Tymiński, T., Kałuża, T., 2012. Investigation of mechanical properties and flow resistance of flexible riverbank vegetation. Polish Journal of Environmental Studies, 21(1): 201-207.
van Wesenbeeck, B.K. et al., 2022. Wave attenuation through forests under extreme conditions. Scientific reports, 12(1): 1884.
Wang, H.-C., Worley, W.J., 1966. Tables of natural frequencies and nodes for transverse vibration of tapered beams.
Wang, J., He, G., Dey, S., Fang, H., 2022. Influence of submerged flexible vegetation on turbulence in an open-channel flow. Journal of Fluid Mechanics, 947: A31.