Modeling Saltwater Intrusion into Groundwater Using a Prey–Predator Model

Abstract

Saltwater intrusion in a coastal region is one of the major issues facing the agricultural, domestic, and industrial sectors. Groundwater withdrawal for an increasing population and agricultural and industrial demands are the main reasons for saltwater intrusion into coastal aquifers. Saltwater intrusion into freshwater aquifers directly affects a population’s health, economy, and social development. This study explores an innovative approach to modeling saltwater intrusion into freshwater using a prey–predator model. Freshwater is analogized as the prey and saltwater as the predator, providing a unique perspective on understanding this phenomenon. The present model was formulated using a balance of freshwater and saltwater and is applicable to coastal aquifers. An amount of freshwater withdrawal such that the volume of saltwater does not produce adverse impacts is predicted graphically. Based on a certain simulation, the current model suggests that if the withdrawal rate drops to 50%, freshwater is projected to surpass saltwater dominance for about 90 years. The model has been validated through a benchmark saltwater intrusion problem.