A Meshless Approach for Modeling Water Infiltration in Heterogeneous Soils

In various scientific and engineering domains, the prediction of soil water infiltration and fluid flow in unsaturated soils are significant issues. In addition, the unsaturated zone is the transfer point for various pollutants from the soil surface to groundwater. In this paper, the groundwater flow is described by the h-form Richard's equation. We aim to simulate water infiltration through heterogeneous soils using a meshless method based on Radial Basis Functions (RBF) with Picard iterations combined with the proper orthogonal decomposition. The heterogeneity is represented by the random behavior of the saturated hydraulic conductivity. This later is treated as a lognormally distributed random field, and the Karhunen-Loève (K-L) decomposition is used to generate it. In general, the results demonstrate that the proposed numerical method provides a remarkably accurate solution to infiltration problems in unsaturated soils with uncertain saturated hydraulic conductivity.