The paper presents a numerical model of transient, saturated-unsaturated water flow through a porous medium. The model solves Richards' equation, which is assumed to present water flow in both unsaturated and saturated zones. The equation is solved by the implicit iterative finite difference method, using the over-relaxation technique. The model is tested by comparison with published laboratory experiments. The agreement between measured and computed values is very good for both infiltration and drainage experiments. The purpose of the model is the prediction of a soil-water regime either in natural conditions or under the influence of an irrigation or drainage system.
- numerical model
- Unsaturated flow