Steady Downward Flow to a Water Table

A partially saturated zone in a porous medium is usually found above a water table when the rate of downward flow per unit area of cross section is less than the hydraulic conductivity of the porous medium. Theoretical solutions describing the distribution of capillary pressure above the water table during steady downward flow are presented. Experiments were conducted, using water as the wetting fluid and air as the nonwetting fluid, for both homogeneous and stratified media. The experimental results show good agreement with the theory. (Key words: Porous media; ground water; hydraulics).