A multi-objective simulation-optimization model constrained by the potential seawater intrusion

A linked simulation-optimization model (SWT-NPTSGA) using the niched Pareto tabu search combined with a genetic algorithm (NPTSGA), is developed for deriving multiple objective management strategies for coastal aquifers, involving seawater intrusion control, mitigation measures, and groundwater resources optimization. The superiority of the NPTSGA-based optimization approach lies in its ability to find the appropriate balance between diversity and convergence of solutions with high computational efficiency. Density-dependent groundwater flow and solute transport simulator SEAWAT is used to generate input-output patterns of groundwater extraction rates and salinity levels. The performance of the presented simulation-optimization model is evaluated through a synthetic example application. The main advantage of the developed model is that it can make a tradeoff among maximization of total pumping rate, minimization of total artificial recharge and minimization of the extent of seawater intrusion. The seawater intrusion mitigation measures by artificial recharge can increase groundwater supply and reduce the area of seawater intrusion. The optimization results show potential feasibility of the proposed methodology in solving multiple objective optimization models for managing coastal aquifers.