Simulation of Seawater intrusion in Coastal confined aquifer using a Point Collocation based Meshfree Method.

Alice Thomas, T.I Eldho, A .K. Rastogi, Partha Majumdar

Monday 29 june 2015

16:45 - 17:00h at Central America (level 0)

Themes: (T) Special session, (ST) Smoothed particle hydrodynamics and other meshfree methods

Parallel session: 3H. Special session: Smoothed Particle Hydrodynamics and other meshfree methods

Proper management of groundwater in coastal aquifers is vital as it is a major source of water supply in various regions. Seawater intrusion caused by groundwater over-exploitation from coastal aquifers is a severe problem that affects the economy, environment and even daily lives of people living near the coast. Formulation of a proper pumping strategy using a simulation model can assure a long term supply of fresh water from the coastal aquifers. The present study focuses on the development of a numerical model based on Meshfree (MFree) method to study the sea water intrusion. For the simulation of sea water intrusion problem, widely used numerical models are based on Finite Difference Method (FDM) and Finite Element Method (FEM), which require well defined grids or meshes and large efforts in pre-processing. In this study, a recently developed MFree method called Point Collocation Method (PCM) is proposed for the simulation of sea water intrusion problem. MFree PCM model for sea water intrusion is based on the Radial Basis Function (RBF). The diffusive interface modelling approach is adopted in this study. In the density dependent dispersion modelling approach, there are two partial differential equations involving flow and solute transport to be solved simultaneously. Along with these partial differential equations, as solute concentration is a function of density, the constitutive equation relating fluid density to concentration is also required. These equations are solved using PCM MFree technique with appropriate boundary conditions. The developed model has been verified with steady state Henry’s problem. Solutions are found to be satisfactory. The model is found computationally efficient as preprocessing is avoided when compared to the other numerical methods.