During rainfall infiltration process, the groundwater flow in saturated‐unsaturated zone of slope is a two‐phase seepage process of water and gas. Considering Buckley‐Leverett equation, a new mathematical model for saturated‐unsaturated seepage in rock and soil media was presented with the foundation of two‐phase seepage equation of continuity and Darcy’s law. The equations are discretized with finite difference dynamical method, based on which, a new three‐dimensional program is developed. Seepage process in a slope under rain condition...
