movement of water through the soil (contrast with infiltration).
percolation (Wikipedia)
In physics, chemistry, and materials science, percolation (from Latin percolare 'to filter, trickle through') refers to the movement and filtering of fluids through porous materials. It is described by Darcy's law. Broader applications have since been developed that cover connectivity of many systems modeled as lattices or graphs, analogous to connectivity of lattice components in the filtration problem that modulates capacity for percolation.
