Incipient motion of sediment in rectangular open-channel flow with a submerged rigid vegetation zone

Abstract

An experimental statistical method is here developed to investigate the incipient motion in open channel blocked with an artificial submerged rigid vegetation patch. We focus on the effects of vegetation elements on the incipient motion of sediment and the scour around the vegetation elements. The incipient motion of sediment is divided into three processes, the static, the partially motion, and the entirely motion, and the third process is defined as the criterion for incipient motion of sediment. Based on the experimental results, a semi-empirical equation for the sediment incipient velocity in the presence of submerged vegetation is derived, which is observed to be smaller than that without vegetation. A strong linear relationship between the average depth of the scour holes around the vegetation elements and the flow velocity is found.

A Study on the Influence of Submergence Ratio on the Transport of Suspended Sediment in a Partially Vegetated Channel Flow

“…It is interesting to note that Xue et al. (2017) proposed a predictive model for the incipient sediment motion by doing a series of experiments with similar flow conditions to the present studies' flow condition. Xue's model is suitable for linear (uniform) rigid submerged vegetation with SR from 0.5 to 0.8, the vegetation density from 0.011 to 0.031 and the diameter of particle from 0.5 to 1.0 mm.…”