Infiltration Process of Rainfall with Constant Intensity

In order to disclose the infiltration process of rainfall into the ground, the infiltration phenomenon is investigated theoretically and experimentally under the conditions that the homogeneous sand layer is bounded at its lower boundary and initially has a uniform moisture profile, and that the rainfall with constant intensity continues. After finding out the approximate solution for a set of fundamental equations with respect to the movement of water and pore-air in the layer, the criterion of ponding on the sand surface, the moving velocity of wetting front, the equation of infiltration rate and so on are presented in comparison with the results of experiment.