(371a) Integrated Mathematical Models for Freshwater Bodies and Constructed Wetlands as Tools for Restoration Planning Through an Optimal Control Approach
The first step in the remediation of eutrophication is nutrient loading reduction into lakes, by means of constructed wetlands. These artificial ecosystems are portions of land covered with macrophytes, which assimilate nutrients, plankton and other microorganims. Estrada et al. (2011) and Di Maggio et al. (2016) formulated water quality models as dynamic optimization problems for the determination of restoration strategies in eutrophic water bodies.
In this work we propose the integration of lake models to artificial wetland models within a dynamic optimization framework to address the optimal design of constructed wetlands as well as determination of optimal restoration policies. Mechanistic wetland models are integrated to lake models to obtain wetland sizing and nutrient dynamics, together with phytoplankton, zooplankton, piscivorous and herbivorous fish abundance profiles. The resulting model is an optimal control problem subject to a differential algebraic equation system. Numerical results provide optimal areas of constructed wetlands and temporal profiles of control and state variables for both lake and wetlands, before and after remediation.