Saltwater intrusion processes in coastal aquifers – modelling and management: a review

Abstract

Saltwater intrusion in coastal aquifers due to human intervention has become a major challenge in different parts of the world. This review highlights some of the factors influencing saltwater intrusion processes in coastal aquifers, and discusses the methodologies proposed for development of management strategies on a regional scale, utilizing solutions of mathematical models. In recent years, significant advancements have been made in the development of mathematical tools for evolving optimal management strategies aimed at controlling saltwater intrusion in coastal aquifers. This article also reviews different modelling techniques utilized, and offers a brief account of management strategies prescribed by several researchers. Two types of modelling approaches exist in the literature: descriptive models aiming at simulating the physical processes analytically or numerically for evaluating the impact of a chosen management strategy, and prescriptive models for choosing optimal aquifer management strategies. Recent trend is to develop artificial-intelligence-based surrogate models trained by using random inputs and corresponding numerical outputs in order to develop coastal aquifer management strategy. Therefore, different surrogate modelling approaches aimed at reducing the computational burden in a linked simulation-optimization methodology are also highlighted in this review. Furthermore, this review provides a brief outline of the development of methodologies for optimal monitoring network design and sequential compliance monitoring of the real life consequences of implementing prescribed management strategies for coastal aquifers.