Coastal Aquifer Management Models: A Comprehensive Review on Model Development

Abstract

The demand for fresh water is accelerating as the world population is increasing in alarming rate. In order to cope with the increased demands, the overexploitation of groundwater resources has become unavoidable in many parts of the world. It has been reported that at least 70 % of the world population is living in coastal areas. The main sources of fresh water for these people are the freshwater aquifer near the coastal region. The unplanned exploitation of freshwater from coastal aquifers, hydraulically connected with sea or ocean may cause saltwater intrusion into coastal aquifers. The saltwater intrusion in coastal aquifers contaminates the aquifers and makes the coastal aquifers unusable for further human utilization. The contamination of coastal aquifers may also cause serious consequences on environment, ecology, and the economy of the region. The remediation of contaminated aquifers is generally very expensive and time-consuming. In order to protect the vital resource, it is necessary to protect coastal aquifers from further contamination by saltwater intrusion. Saltwater intrusion can be controlled by suitable management policies. The main objective of a coastal aquifer management model is to evolve planned operational strategies to meet required demand of fresh water while maintaining the salinity of water within permissible limit. In order to evolve a physically meaningful strategy, the flow and transport processes need to be simulated within the optimization-based management model. Different methodologies like embedded optimization method, response matrix approach, linked simulation optimization method, etc., have been developed to incorporate the aquifer simulation models with the management model. These methods have their own advantages and disadvantages and none of the methods can be declared as the best method for solving coastal aquifer management models. As such, a suitable method should be selected based on the data availability and other related local advantages. The study presents a review on development of coastal aquifer management models.