Saltwater Intrusion in Coastal Aquifers: A Comprehensive Review and Case Studies from Egypt

Abstract

There is no doubt that groundwater plays an essential role in people’s lives, especially in coastal areas. Therefore, it is very important to tackle this vital source of water from a strategic point of view and provide a management plan to conserve it at an ideal state. Moreover, the salination of groundwater is a serious matter that faces coastal communities due to the excessive pumping of groundwater from coastal aquifers, decrease in recharge, sea level rise, climate change, and other causes. Saltwater intrusion (SWI) is one of the most common problems that must be put into consideration, and it is considered a major risk to groundwater quantity and quality. It occurs when saline water is allowed to enter coastal aquifers to cause contamination of freshwater storage. The main objective of this review article is to highlight the definition of this phenomenon, its causes, the factors affecting it, and different monitoring techniques. In addition, different modeling methods, and management tools, including remote sensing, field surveys, modeling methods, and optimization techniques, are discussed. To avoid the harmful effects of SWI, several countermeasures to control it are illustrated with their advantages and disadvantages. In the final part, Also, some previous work related to SWI worldwide and case studies from the Nile Delta, Sinai Peninsula, and the North-West coast in Egypt will be overviewed. From these research studies, suggestions, adaption, and mitigation measures can be implemented for future studies.