Seawater intrusion modelling is often used to assist with groundwater management in coastal areas and islands.
Although Smoothed Particle Hydrodynamics (SPH) schemes are able to simulate multi-fluid flows in porous
media, they have not been widely tested against experimental observations yet. Additionally, numerical methods
for groundwater flow problems need to be able to simulate pumping, which is an unexplored area in SPH. In this
study, an Explicit Incompressible SPH(EISPH) solver for multi-fluid flow in porous media is used to simulate the
dynamics of freshwater lenses in small islands, and is further developed to simulate groundwater pumping and
associated seawater upconing. Three methods to implement a sink term that models water pumping from an
aquifer are proposed and compared. The model is successfully tested against data from published laboratory-scale experiments and other numerical models. The results of EISPH are comparable to other models. The inclusion of a sink for water particles to simulate pumping did not affect the stability of the simulations, although one of the three methods led to results that better compared to experimental data. Hence, SPH modelling of groundwater flows in porous media can be successfully achieved using the methods developed here.