Depth-averaged simulation of flows in asymmetric
compound channels with smooth and rough
narrow floodplains

Alawadi, WAAK; Tumula, DP

Abstract

Depth-averaged hydrodynamic models are predominantly used in numerical simulations of
compound channel flows. One of the most popular methods for the depth-averaged simulation
is Shiono and Knight method (SKM). This method accounts for the effects of bed friction, lateral
turbulence and secondary flows, via three key parameters f, λ and Γ, respectively. The conventional
expressions that are developed to calibrate these parameters are generally based on
experiments in compound channels with wide floodplains. In this study, the application of SKM
to an asymmetric compound channel with a narrow floodplain is examined in terms of the
calibration requirements. Two sets of experiments that have smooth and rough floodplains are
conducted and then simulated by SKM. In smooth floodplain cases, the results reveal that SKM
model with the conventional calibration expressions of f, λ and Г is reasonably capable of
predicting the distributions of depth-averaged velocity and boundary shear stress in the main
channel. However, in the floodplain region, the expressions recommended for calibrating Г
need to be modified to improve the predicted results in that region. In cases of the rough
floodplain, the results indicate that only the values of λ in the main channel need to be
changed from its conventional values to improve the predictions.

Citation

narrow floodplains. Australasian Journal of Water Resource, 22(2), 137-148. https://doi.org/10.1080/13241583.2018.1509766

• Journal Article Type: Article
• Acceptance Date: Aug 6, 2018
• Online Publication Date: Sep 2, 2018
• Publication Date: Sep 2, 2018
• Deposit Date: Nov 27, 2018
• Publicly Available Date: Sep 2, 2019
• Journal: Australasian Journal of Water Resources
• Print ISSN: 1324-1583
• Electronic ISSN: 2204-227X
• Publisher: Taylor and Francis Group
• Volume: 22
• Issue: 2
• Pages: 137-148
• DOI: https://doi.org/10.1080/13241583.2018.1509766
• Publisher URL: https://doi.org/10.1080/13241583.2018.1509766
• Related Public URLs: https://www.tandfonline.com/action/journalInformation?journalCode=twar20