Advances in Computational Fluid Dynamics models for Horizontal Surface Flow Wetlands: porous media vs plant direct representation

This study aims to contribute to the improvement of Horizontal Surface Flow Wetlands hydrodynamics simulations through the evaluation of different approaches to consider the effect of plants on wetland hydraulics. Two scenarios were assessed in this study. Scenario 1 represents vegetation using an adapted method for porous media simulation. Scenario 2, in turn, adopts the direct plant representation, which consists in incorporate vegetation in the simulation as discrete obstacles inside the wetland. From the results, it is noted that scenario 1 provides a limited overview of the impact of plants on wetland hydrodynamics. On the other hand, results from scenario 2 show a much better detailing of local flow patterns. So, from the results direct plant simulation seems to be a promising approach to support surface flow design optimization, enabling to catch local phenomenon as dead zones and preferential flow pathways.