Two-dimensional meshless simulation of contaminant transport in porous media using the generalized finite difference method (GFDM)

Groundwater is the most dependent source of irrigation and public water supply in most countries; hence, it requires the best quality management practices to safeguard against contamination. Groundwater quality management requires the best models to assess the extent of migration and spatiotemporal variation.  The extent of contamination is often studied through the application of mesh-based methods, such as the finite difference method (FDM) and the finite element method (FEM). Moreover, in recent decades, various groundwater meshless studies have provided better alternatives to mesh-based methods for solving complex groundwater contamination problems. The meshless methods eliminate the need for generating a computational mesh; they operate on a set of scattered nodes distributed across the aquifer domain, which can be easily added or removed as needed, depending on the field scenario and its complexity. Recent studies have demonstrated the development of various meshless methods for modeling groundwater contaminant transport, enabling the assessment of transport behavior. In this study, a groundwater contaminant transport model is developed using the generalized finite difference method (GFDM), which employs the Taylor series and the moving least squares (MLS) method to determine the spatial and temporal variations of contaminant in the aquifer domain. The application of the developed GFCT model is demonstrated for various heterogeneous porous media, and the results are compared with those from the MT3DMS model.