An Examination of Dispersion in Low Reynolds Number Stormwater Wetlands

Stormwater is an important environmental concern. Constructed Stormwater Wetlands (CSWs) are at tool in stormwater management, however little is known about the dispersion coefficient in laminar flow conditions. This study replicates two laboratory studies examining the dispersion coefficient as it relates to the plant density in laminar flow conditions. Nepf et al. examined plant densities from 0 to 5.3% and Serra et al. examined plant densities between 10 and 30%. The Villanova University field study examined plant densities between 3 and 10%. The present experiment provided the opportunity to examine the gap in plant densities and examine the effect of field conditions. The results indicate that the dispersion coefficients from the field experiments are one to two orders of magnitude higher than the laboratory experiments. The hydrodynamic modeling software Mike 21 is being used to confirm and quantify this theory.