Velocity Profile and Lateral Distribution in an Open Channel with Two Distinct Vegetative Zones

Xiaonan Tang, Yutong Guan, Yuxiang Hu

2021

Abstract

Riparian vegetation has drawn increasing attention because it plays a vital role in the ecological environment and flow process in river systems. Previous literature on vegetative flow mostly focuses on understanding the hydraulic feature of uniform single-layered vegetation in a channel. In many rivers, vegetation often grows unevenly along riversides, on which very few studies have been done. For understanding the effect of unevenly distributed vegetation on the flow, this paper presents novel experimental results in an open channel with each side of the bed occupied by different height vegetation. The vegetation was mimicked by dowels 10 cm and 20 cm high and in two flow conditions: fully and partially submerged. A micro ADV (Acoustic Doppler Velocimetry) was used to measure 3D velocities at various positions. Observed data show that the averaged velocity profile in the non-vegetative region (free-flow zone) is influenced by neighboring vegetative regions, where the velocity reflects at some distance below the top of vegetation. A large lateral velocity gradient exists near the interfacial boundary between vegetative and non-vegetative flow regions, indicating that a transition layer occurs near the interfacial boundary owing to the momentum exchange. Moreover, with the increasing flow depth, the zonal velocity in the non-vegetative region decreases slightly while the zonal velocity increases accordingly in the vegetative region (either short or tall vegetation sub-region), indicating that the averaged velocity in the vegetative region is affected by the submergence of vegetation. These findings on the channel flow with unevenly layered vegetation would benefit riparian management and the design of ecological and habitat zones in terms of the width and height of vegetation.

Paper Citation

in Harvard Style

Tang X., Guan Y. and Hu Y. (2021). Velocity Profile and Lateral Distribution in an Open Channel with Two Distinct Vegetative Zones. In Proceedings of the 7th International Conference on Water Resource and Environment - Volume 1: WRE, ISBN 978-989-758-560-9, pages 240-245

in Bibtex Style

@conference{wre21,
author={Xiaonan Tang and Yutong Guan and Yuxiang Hu},
title={Velocity Profile and Lateral Distribution in an Open Channel with Two Distinct Vegetative Zones},
booktitle={Proceedings of the 7th International Conference on Water Resource and Environment - Volume 1: WRE,},
year={2021},
pages={240-245},
publisher={SciTePress},
organization={INSTICC},
doi={},
isbn={978-989-758-560-9},
}

in EndNote Style

TY - CONF

JO - Proceedings of the 7th International Conference on Water Resource and Environment - Volume 1: WRE,
TI - Velocity Profile and Lateral Distribution in an Open Channel with Two Distinct Vegetative Zones
SN - 978-989-758-560-9
AU - Tang X.
AU - Guan Y.
AU - Hu Y.
PY - 2021
SP - 240
EP - 245
DO -