Lodging Velocity for an Emergent Aquatic Plant in Open Channels

Abstract

Vegetation can impede flow in open channels. The control of vegetation by hydraulic means is a nonchemical approach that can be attractive. To control the vegetation, the calculation of the lodging velocity (velocity at which the plant stem breaks) is an important parameter. A theoretical method is developed here for a single stem fully exposed to the flow, assuming that the drag force is the sole failure-inducing force. Results are compared to field results and the trends analyzed. The comparison and field visual observations may indicate that vortex shedding (not accounted for in the model) could be the dominant failure-inducing force, and not the drag force, as assumed.