Effects of Stem Density and Reynolds Number on Fine Sediment Interception by Emergent Vegetation

Suspended sediment collected by vegetation in marshes and wetlands contributes to vertical accretion, which can buffer against rising sea levels. Effective capture efficiency (ECE), a parameter quantifying the fraction of incoming suspended particles directly captured underwater surfaces, plays key role determining significance direct interception morphodynamic models. The ways physical characteristics collectors transitionally turbulent flows affect ECE are not yet thoroughly understood. We conducted set 12 experiments at three flow velocities stem densities (plus equivalent zero-collector control experiments), plus four where biofilm was allowed accumulate. determined that decreases with increasing collector Reynolds number (study range: 66 200; p < 0.05 for two treatments) density (solid volume fraction: 0.22% 1.17%; treatments). Adding increased all cases, multiplicative factor ranging from 1.53 7.15 different growth durations. In some impact on far outweighed density. By combining our data those one similar study, we present preliminary model quantitatively assessing effect ECE.