Numerical modelling and control of seawater intrusion in coastal aquifers

This paper presents the results of an investigation into numerical modelling and control of seawater intrusion. A coupled transient density-dependent finite element model has been used for modelling of seawater intrusion. Also, a new costeffective method is presented for effective control of seawater intrusion in coastal aquifers. This methodology ADR (Abstraction, Desalination and Recharge) includes abstraction of saline water, desalination and recharge of a part of the excess desalinated water to the aquifer while the rest of the desalinated water can be used for domestic consumption. The simulation model has been integrated with an genetic algorithm (GA) to examine different scenarios to control seawater intrusion including different combinations of abstraction, desalination and recharge. The main objectives of the model are to minimize the total capital and operational costs of the abstraction and recharge wells and the salt concentrations in the aquifer. The results show that the proposed ADR system performs significantly better than using abstraction or recharge wells alone as it gives the least cost and least salinity in the aquifer.