journal article Sep 07, 2022

Experimental investigation of 3D flow properties around emergent rigid vegetation

Ecohydrology Vol. 15 No. 8 · Wiley
Abstract
AbstractThe condition of emergent or submerged vegetation plays a vital role in affecting the flow behaviour in open channels. To understand the flow processes in free surface flows under emergent rigid vegetation condition, an extensive experimental investigation is performed in a laboratory channel with staggered combination of emergent rigid vegetation. Three‐dimensional velocities data are collected by ADV at various section and position of vegetated channel. The three‐dimensional flow properties such as velocity distribution, turbulence intensity, turbulent kinetic energy, Reynolds shear stress in vegetation, and non‐disturbed region are analysed and compared with the longitudinal and transverse length of vegetated zone. In the vegetation region, the longitudinal velocity in free stream region decreases as compared with non‐disturbed region. However, the vertical velocity also decreases in free stream region except at the centre line of channel cross‐section. Variations in velocity in the vegetation section were observed because of the local effect induced by the vegetation stems. Three‐dimensional Reynolds shear stress and turbulent intensity were weaker in magnitude at vegetation region. The presence of vegetation reduces the longitudinal profile of flow velocity, Reynolds shear stress and turbulence intensities, which means that vegetation can be used as an effective tool to reduce the flow resistance. The turbulent kinetic energy, skewness and kurtosis are also evaluated and compared between the vegetated and non‐vegetated zone. The outcomes of the results provide an important view to understand flow behaviour at immediately front and immediately behind of vegetation stem.
Topics

No keywords indexed for this article. Browse by subject →

References
70
[4]
Buckman L. J.(2013).Hydrodynamics of partially vegetated channels: Stem drag forces and application to an in‐stream wetland concept for tropical urban drainage systems.
[11]
Chow V. T. (1959)
[15]
Devi T. B. "Studies on emergent flow over vegetative channel bed with downward seepage" Hydrological Sciences Journal (2017)
[19]
Freeman G. E. Rahmeyer W. H. &Copeland R. R.(2000).Determination of resistance due to shrubs and woody vegetation. Coastal and Hydraulics Laboratory (US) ERDC. CHL TR‐00‐25. 10.21236/ada383997
[20]
Despiking Acoustic Doppler Velocimeter Data

Derek G. Goring, Vladimir I. Nikora

Journal of Hydraulic Engineering 10.1061/(asce)0733-9429(2002)128:1(117)
[33]
Meijer D. G. &Van Velzen E. H.(1999).Prototype‐scale flume experiments on hydraulic roughness of submerged vegetation. In 28th International Conference Int. Assoc. of Hydraul. Eng. and Res. Graz Austria.
[35]
Nehal L. Hamimed A. &Khaldi A.(2013).Experimental study on the impact of emergent vegetation on flow. In Proc. 7th International Water Technology Conference IWTC17 Istanbul (http://iwtc.info/wp-content/uploads/2013/11/94.pdf) (p. 6).
[36]
Drag, turbulence, and diffusion in flow through emergent vegetation

H. M. Nepf

Water Resources Research 10.1029/1998wr900069
[40]
Turburence structure and coherent motion in vegetated canopy open-channel flows

Iehisa Nezu, Michio Sanjou

Journal of Hydro-environment Research 10.1016/j.jher.2008.05.003
[41]
Ni H. G. "Roughness coefficient of non‐submerged reed" Journal of Hydrodynamics, Ser. A (2005)

Showing 50 of 70 references

Cited By
28
AQUA — Water Infrastructure, Ecosys...
Environmental Fluid Mechanics
Metrics
28
Citations
70
References
Details
Published
Sep 07, 2022
Vol/Issue
15(8)
License
View
Cite This Article
Pritam Kumar, Anurag Sharma (2022). Experimental investigation of 3D flow properties around emergent rigid vegetation. Ecohydrology, 15(8). https://doi.org/10.1002/eco.2474