Sediment Pickup Rate in Bare and Vegetated Channels

Understanding the influence of vegetation on flow and sediment transport is essential to wetland protection and restoration projects. Laboratory experiments were conducted to investigate the sediment pickup (or entrainment) over bare and vegetated beds with model vegetation (i.e., cylinder arrays) of different solid volume fractions, (Formula presented.), and diameters, (Formula presented.). For the vegetated beds, measured pickup rate was closely correlated with turbulent kinetic energy, (Formula presented.), and (Formula presented.) -based model developed for bare channels significantly underestimated the pickup rate measured in vegetated channels. Building on previous theoretical analyses and observations, this study proposed two (Formula presented.) -based predictions for pickup rate that include the impact of both bed- and vegetation-generated turbulence. The new models improve the prediction of pickup rate within vegetated regions.