An improved formula for incipient sediment motion in vegetated open channel flows

Quantifying incipient sediment motion in vegetated open channel flow is pivotal for estimating bed load transport and the aquatic ecological environment in rivers. A new formula is developed to predict the critical flow velocity for incipient sediment motion in the presence of emergent vegetation, by incorporating the influence of vegetation drag that characterizes the effects of mean flow and turbulence on sediment movement. The proposed formula is shown to agree with existing experimental data. Moreover, the proposed formula is extended to scenarios with submerged vegetation, suggesting that the vegetation drag may be the inherent impact factor for incipient sediment motion in vegetated open channel flow (c) 2021 International Research and Training Centre on Erosion and Sedimentation/the World Association for Sedimentation and Erosion Research. Published by Elsevier B.V. All rights reserved.

Automated summary

A new formula is developed to predict the critical flow velocity for incipient sediment motion in the presence of vegetation, taking into account the influence of vegetation drag. The formula shows agreement with existing experimental data and can be extended to scenarios with submerged vegetation.