Wind Shielding Impacts on Water Quality in an Urban Reservoir

This study applied an atmospheric Computational Fluid Dynamics (CFD) model and a three-dimensional hydrodynamic-ecological lake model to investigate the impacts of variable wind forcing on lake hydrodynamics and water quality. The CFD model was used to predict the wind field over the lake surface which served as the meteorological forcing for the lake model. The study was carried out for the Marina Reservoir in downtown Singapore where field measurements of the wind field showed that temporal and spatial differences in wind field were found to be significant. By comparing simulations using uniform and spatially variable wind inputs in terms of thermal stratification, Richardson number, vorticity, and spatial gradients, this study demonstrates that the variability in wind forcing in urban lakes that arise from shielding and seasonal effects can have significant impacts on the hydrodynamics and water quality in the reservoir.