A review of groundwater sustainability crisis in the Pacific Island countries: Challenges and solutions

Population growth and rapid industrialization have imposed excessive demand for groundwater in Pacific Island countries (PICs). To meet this demand, over pumping of groundwater is practised in majority of the PICs, which eventually causes saltwater intrusion (SWI) in coastal aquifers. The geographical location of PICs makes them more vulnerable to natural means of SWI. However, anthropogenic activities also cause groundwater contamination in PICs. The main objectives of this review are to identify the water sources in PICs, the major challenges groundwater faces, and solutions or strategies for monitoring, management, and prevention of the identified challenges. This study has revealed that SWI is highly common in PICs and that there is a knowledge gap with limited research on groundwater. This review also highlights that with the use of the latest technologies, 3D modeling, simulation-optimization techniques, artificial intelligence, relevant policies and regulations on groundwater and mass awareness will help in monitoring, managing and preventing SWI and other ways of contamination in coastal aquifers for PICs.