Introduction

Infiltration into unsaturated soil is a problem of great interest in the fields of hydrology, soil science, agricultural science, and geotechnical engineering. Some typical examples of practical problems include water movement in pavement sections, contaminant transport through the unsaturated zone, soil cover design, and irrigation and drainage studies. Interestingly, finite element solutions to infiltration problems involving dry soil can exhibit numerical problems (e.g. oscillation), mass balance errors, and can converge to the wrong solution. This deceptively simple problem is complicated by highly nonlinear hydraulic properties and relatively large pressure head gradients across the wetting front.

The objective of this example file is to benchmark SEEP/W against a semi-analytical solution for one-dimensional infiltration in unsaturated soil developed by Warrick et al. (1985). Details of the solution can be found in the original publication.