Moisture variation at the soil surface and the advance of the wetting front during infiltration at constant flux

Abstract

The problem of infiltration at constant flux at the soil surface has been solved approximately in an analytical closed form. The solutions may be valuable to the practicing engineer when dealing with sprinkler irrigation or infiltration of rain. Infiltration into a semi‐infinite soil column as well as infiltration into a soil column of finite length with a constant water table were considered. Analytical and numerical results were compared for a few cases. It was found that the analytical solutions provide quite a satisfactory prediction of the moisture content at the soil surface and the advance of the wetting front. The results are presented in a dimensionless form; the analytical results are the same for all soils, and apparently the numerical results are also the same for all soils.