Analytical Solutions for Contaminant Transport in Wetlands Incorporating Surface Water and Groundwater Interactions

Wetlands are the transitional zones between uplands and downstream flooded systems; they play an important role in controlling storm water peak flow and downstream water quality. Since surface water/subsurface water interactions affect solute transport within wetlands significantly, contaminant transport models incorporating these interactions need to be investigated for wetland areas. Wetland solute transport dynamics (WETSAND) is a comprehensive wetland model, which has both surface flow and solute transport components. In WETSAND, water quality components are solved by advection-dispersion-reaction equations, which incorporate surface water/groundwater interactions by including the incoming/outgoing mass due to the groundwater recharge/discharge. In this study, analytical solutions for the contaminant transport equations of WETSAND are developed and compared to the numerical solutions obtained by WETSAND. These analytical solutions provide a physical insight to wetland water quality. Results show that analytical solutions are in good agreement with the numerical solutions. Moreover, the effect of interactions on wetland water quality is discussed. (C) 2014 American Society of Civil Engineers.