Three-Dimensional Model of Coupled Density-Dependent Flow and Miscible Salt Transport

Abstract

Saltwater intrusion in coastal aquifers is a very serious threat to subsurface water quality worldwide. This contamination of freshwater resources occurs, in a typical scenario, when the wide cone of depression formed by extensive groundwater pumping comes into contact with underlying or surrounding seawater. Twenty years ago Newport [1977] reported that at least twenty coastal areas in the United States were contaminated by saline water. Documented cases have since been reported for many other countries. Contamination by salt deteriorates water quality dramatically. A two to three percent mixing with seawater makes freshwater unsuitable for human consumption, and five percent mixing makes it unusable for irrigation as well [Custodio et al., 1987; Sherif and Singh, 1996].