Mathematical Models to Control Saltwater Intrusion in Coastal Aquifers

Abstract

Saltwater intrusion is a major problem in the coastal regions all over the world. It is common in coastal areas where the aquifers are in hydraulic contact with the sea. Under normal conditions without any anthropogenic activity, the freshwater flows into the sea. However, over-pumping may result in inversion of the groundwater flow from the sea towards the inland causing saltwater intrusion. Salinization of groundwater is considered a special category of pollution that threatens groundwater resources, because mixing a small quantity (2 percent) of saltwater with groundwater makes freshwater unsuitable and can result in abandonment of freshwater supply. Therefore, saltwater intrusion should be prevented or at least controlled to protect groundwater resources. This paper discusses various alternatives to control saltwater intrusion and different mathematical models that have been developed for this purpose in the Middle East, South Europe, and USA. The paper aims to analyse the benefits and limitations of these models considering physical constraints, practical and economical aspects, and environmental impacts. Finally, this study suggests a new method to control saltwater intrusion in order to overcome the previous limitations. This method is economical, has less environmental impact and can be used for sustainable development of water resources in coastal areas.