Numerical analysis of physical barriers systems efficiency in controlling saltwater intrusion in coastal aquifers.

Saltwater intrusion (SWI) increases salinity of aquifers and depletion of groundwater resources in coastal aquifers. Different methods have been used to control SWI in the coastal aquifers in order to protect groundwater. In this paper, applicability of physical subsurface barriers (PSB) methods to control SWI in the Biscayne aquifer in Florida, USA, is studied. Numerical models have been developed to study and compare performance of two types of the PSB namely cutoff wall and subsurface dam for SWI control. The developed numerical models have been verified through simulation of benchmark examples and then have been used to simulate a semi-hypothetical case study relying on hydrogeological data measured in the Biscayne aquifer. Different scenarios of barriers depths, locations, and permeability have been analyzed. The results indicated that the PSB can effectively control the intrusion of saline into coastal aquifers. However, cutoff wall gave higher retardation than sub-surface dams.