The importance of riparian plant orientation in river flow implications for flow structures and drag.pdf (3.01 MB)
The importance of riparian plant orientation in river flow: implications for flow structures and drag
journal contribution
posted on 2019-01-30, 16:20 authored by Richard J. Boothroyd, Richard J. Hardy, Jeff Warburton, Tim MarjoribanksTim MarjoribanksIn a series of high resolution numerical modelling experiments, we incorporate submerged riparian plants into a Computational Fluid Dynamics (CFD) model used to predict flow structures and drag in river flow. Individual plant point clouds were captured using Terrestrial Laser Scanning (TLS) and geometric characteristics quantified. In the first experiment, flow is modelled around three different plant specimens of the same species (Prunus laurocerasus). In the second experiment, the orientation of another specimen is incrementally rotated to modify the flow-facing structure when foliated and defoliated. Each plant introduces a unique disturbance pattern to the normalised downstream velocity field, resulting in spatially heterogeneous and irregularly shaped velocity profiles. The results question the extent to which generalised velocity profiles can be quantified for morphologically complex plants. Incremental changes in plant orientation introduce gradual changes to the downstream velocity field and cause a substantial range in the quantified drag response. Form drag forces are up to an order of magnitude greater for foliated plants compared to defoliated plants, although the mean drag coefficient for defoliated plants is higher (1.52 defoliated; 1.03 foliated). Variation in the drag coefficients are greatest when the plant is defoliated (up to ~210% variation when defoliated, ~80% when foliated).
Funding
Richard J. Boothroyd was funded under NERC Doctoral Scholarship 1313876.
History
School
- Architecture, Building and Civil Engineering
Published in
Journal of EcohydraulicsCitation
BOOTHROYD, R.J. ... et al, 2019. The importance of riparian plant orientation in river flow: implications for flow structures and drag. Journal of Ecohydraulics, 3 (2), pp.108-129.Publisher
Taylor and Francis © The Author(s). International Association for Hydro-Environment Engineering and ResearchVersion
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/Acceptance date
2019-01-17Publication date
2019-04-05Notes
This is an Open Access article. It is published by Taylor & Francis under the Creative Commons Attribution 4.0 International Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/ISSN
2470-5357eISSN
2470-5365Publisher version
Language
- en