System dynamics modeling with sensitivity analysis for floating treatment wetlands in a stormwater wet pond

Abstract

Rapid urbanization and climate variability impacts increase with more extreme precipitation and drought events, challenging stormwater management in terms of both flood control and water quality. Traditional stormwater wet detention ponds have limited capacity to remove nutrient pollutants, specifically nitrogen, and the changing environment may exacerbate the problem. The use of floating treatment wetlands (FTWs) may become a viable best management practice to increase the efficiency for on-site removal of nitrogen pollution from traditional stormwater wet detention ponds before release into neighboring aquatic systems or to the groundwater. This study, which is deemed a companion study of the early ecological engineering practice of FTWs, presents a system dynamics model to improve understanding of the nitrogen cycle in relation to FTWs-based subtropical stormwater wet detention ponds. The model was calibrated and validated based on surface water samples collected in a thorough field campaign with R-squared values of 0.83 and 0.97, respectively. Final simulation runs with sensitivity analysis were conducted to investigate scientific questions about the experimental design and effects of urbanization impacts on the biological nitrogen cycling in stormwater ponds.