Effect of Rigid Aquatic Bank Weeds on Flow Velocities and Bed Morphology
Water • 2023
Publication Information
Authors
Elzahry, E. F. M., Eltoukhy, M. A, Abdelmoaty, M. S., Eraky, O. M., and Shaaban, I. G.
Keywords
side vegetation; density; velocity profile; scour depth
Journal
Water
Publisher
MDPI
Volume
15
Issue
3173
Pages
Not Available
publication.type
International
Paper Link
Open Link
Supplementary Materials
Not Available
Abstract
The prediction of changes in velocity distribution and channel bed morphology is significant in open channel management and design. This paper implements experimental work to realize
and quantify the effect of rigid aquatic bank weeds on vertical velocity profiles and channel bed
morphology. In the experimental work, weeds were given a staggered distribution using three distances of 25, 50, and 75 mm, unilaterally and bilaterally, with Froude numbers ranging from 0.11 to 0.30, achieving 168 scenarios. Results for the tested weed cases showed that the average velocity
was directly proportional to the weed density and approached the Froude number. By comparing the
smooth and weeded velocities, it was found that the velocity inside the infested reach was close to the downstream velocity and exceeded the upstream velocity by about 10% and 41%, respectively. Scour depths along the centerline of the vegetated reach for the bilateral weeds were higher by 11%
to 33% than those for the unilateral weeds. The maximum observed depth of the scour holes along
the smooth bank was about 30% to 60% of the maximum scour depth at the middle line. Finally, to quantify the results, multiple regression analysis was performed to develop empirical equations to assist in the water management process.
and quantify the effect of rigid aquatic bank weeds on vertical velocity profiles and channel bed
morphology. In the experimental work, weeds were given a staggered distribution using three distances of 25, 50, and 75 mm, unilaterally and bilaterally, with Froude numbers ranging from 0.11 to 0.30, achieving 168 scenarios. Results for the tested weed cases showed that the average velocity
was directly proportional to the weed density and approached the Froude number. By comparing the
smooth and weeded velocities, it was found that the velocity inside the infested reach was close to the downstream velocity and exceeded the upstream velocity by about 10% and 41%, respectively. Scour depths along the centerline of the vegetated reach for the bilateral weeds were higher by 11%
to 33% than those for the unilateral weeds. The maximum observed depth of the scour holes along
the smooth bank was about 30% to 60% of the maximum scour depth at the middle line. Finally, to quantify the results, multiple regression analysis was performed to develop empirical equations to assist in the water management process.
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