Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling

For detailed hydrodynamic modelling of vegetated floodplains, the ability to quantify vegetation is advantageous as vegetation significantly influences the flow mechanism. Although it is widely known that roughness changes with depths, many two-dimensional (2D) models assign constant or generic roug...

Full description

Bibliographic Details
Main Authors: Mohd Zahidi, Izni, Yusuf, Badronnisa, Cope, Mike, Mohammed Ali, Thamer Ahmed, Mohd Shafri, Elmi Zulhaidi
Format: Article
Language:English
Published: Taylor & Francis 2018
Online Access:http://psasir.upm.edu.my/id/eprint/72485/
http://psasir.upm.edu.my/id/eprint/72485/1/Effects%20of%20depth-varying%20vegetation%20roughness%20in%20two-dimensional%20hydrodynamic%20modelling.pdf
_version_ 1848857129715236864
author Mohd Zahidi, Izni
Yusuf, Badronnisa
Cope, Mike
Mohammed Ali, Thamer Ahmed
Mohd Shafri, Elmi Zulhaidi
author_facet Mohd Zahidi, Izni
Yusuf, Badronnisa
Cope, Mike
Mohammed Ali, Thamer Ahmed
Mohd Shafri, Elmi Zulhaidi
author_sort Mohd Zahidi, Izni
building UPM Institutional Repository
collection Online Access
description For detailed hydrodynamic modelling of vegetated floodplains, the ability to quantify vegetation is advantageous as vegetation significantly influences the flow mechanism. Although it is widely known that roughness changes with depths, many two-dimensional (2D) models assign constant or generic roughness and the values are typically adjusted for calibration. This practice is likely to lead to the misinterpretation of the flow mechanism. This paper assesses the effects of depth-varying vegetation roughness in 2D hydrodynamic modelling based on vegetation density derived from a remotely sensed regression analysis. The simulated flood extents, depths and velocities of a historical flood event were compared between the constant and depth-varying vegetation roughness coefficients and verified against historical data and literature. A minimum value of 0.03 was found for vegetation with the lowest density of 0.01 m−1 at 0.2 m depth and a maximum value of 0.20 for vegetation with the highest density of 0.20 m−1 at 2 m flow depth, resulting in the maximum differences in flood depths and velocities of 0.40 m and 0.25 m/s, respectively. This study presented a bridge between the theoretical and practical applications which can potentially be used for evaluating vegetation restoration and removal.
first_indexed 2025-11-15T11:52:39Z
format Article
id upm-72485
institution Universiti Putra Malaysia
institution_category Local University
language English
last_indexed 2025-11-15T11:52:39Z
publishDate 2018
publisher Taylor & Francis
recordtype eprints
repository_type Digital Repository
spelling upm-724852020-06-18T14:07:07Z http://psasir.upm.edu.my/id/eprint/72485/ Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling Mohd Zahidi, Izni Yusuf, Badronnisa Cope, Mike Mohammed Ali, Thamer Ahmed Mohd Shafri, Elmi Zulhaidi For detailed hydrodynamic modelling of vegetated floodplains, the ability to quantify vegetation is advantageous as vegetation significantly influences the flow mechanism. Although it is widely known that roughness changes with depths, many two-dimensional (2D) models assign constant or generic roughness and the values are typically adjusted for calibration. This practice is likely to lead to the misinterpretation of the flow mechanism. This paper assesses the effects of depth-varying vegetation roughness in 2D hydrodynamic modelling based on vegetation density derived from a remotely sensed regression analysis. The simulated flood extents, depths and velocities of a historical flood event were compared between the constant and depth-varying vegetation roughness coefficients and verified against historical data and literature. A minimum value of 0.03 was found for vegetation with the lowest density of 0.01 m−1 at 0.2 m depth and a maximum value of 0.20 for vegetation with the highest density of 0.20 m−1 at 2 m flow depth, resulting in the maximum differences in flood depths and velocities of 0.40 m and 0.25 m/s, respectively. This study presented a bridge between the theoretical and practical applications which can potentially be used for evaluating vegetation restoration and removal. Taylor & Francis 2018 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/72485/1/Effects%20of%20depth-varying%20vegetation%20roughness%20in%20two-dimensional%20hydrodynamic%20modelling.pdf Mohd Zahidi, Izni and Yusuf, Badronnisa and Cope, Mike and Mohammed Ali, Thamer Ahmed and Mohd Shafri, Elmi Zulhaidi (2018) Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling. International Journal of River Basin Management, 16 (4). 413 - 426. ISSN 1571-5124; ESSN: 1814-2060 https://www.tandfonline.com/doi/abs/10.1080/15715124.2017.1394313 10.1080/15715124.2017.1394313
spellingShingle Mohd Zahidi, Izni
Yusuf, Badronnisa
Cope, Mike
Mohammed Ali, Thamer Ahmed
Mohd Shafri, Elmi Zulhaidi
Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling
title Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling
title_full Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling
title_fullStr Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling
title_full_unstemmed Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling
title_short Effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling
title_sort effects of depth-varying vegetation roughness in two-dimensional hydrodynamic modelling
url http://psasir.upm.edu.my/id/eprint/72485/
http://psasir.upm.edu.my/id/eprint/72485/
http://psasir.upm.edu.my/id/eprint/72485/
http://psasir.upm.edu.my/id/eprint/72485/1/Effects%20of%20depth-varying%20vegetation%20roughness%20in%20two-dimensional%20hydrodynamic%20modelling.pdf