Solving subsurface flow toward wells in layered soils using hybrid method of fundamental solutions

Abstract

In this article, numerical solutions of three–dimensional subsurface flow toward wells in layered soils using a hybrid method of fundamental solutions is presented. The proposed boundary–type meshless method is based on using the superposition of the fundamental solution and general solution of governing equations from the subsurface flow and the radial flow to a well, respectively. To deal with the subsurface flow in a layered aquifer system, the method of domain decomposition is employed in which the continuity conditions of head and flux at the interface between layers can be satisfied. The validation of the proposed approach is conducted comparing with exact solutions and the USGS's modular hydrologic model, MODFLOW. The approach is then applied to investigate the leakage of the aquifer under pumping conditions for a real layered aquifer system in Taiwan. Results illustrate that the proposed approach exhibits high accuracy over the mesh–based numerical technique. We also demonstrate that the boundary–type meshless method is beneficial for the boundary discretization technique and reduces the computational complexity.