ABSTRACT
Infiltration is the movement of water from the surface into the ground, whether naturally occurring or artificially induced. Quantitative modeling of infiltration and its results is a basis for designing the hydrologic capacities of infiltration surfaces and basins. Infiltration into a homogeneous porous material follows Darcy's law. The application, when fully articulated, is complex because hydraulic gradient varies over time as ponding depth varies and as the matric suction is altered by added water. Bouwer found that infiltration rate into a given dry soil is limited by air trapped in the soil voids, reducing the available porosity into which water can infiltrate. The electrochemical forces at the surfaces of clay particles can bind particles together into larger aggregates, building macropores and increasing conductivity. The use of average monthly data to determine the water balance requires only moderate climatic data input and computing capabilities. Evapotranspiration is not monitored as commonly as other meteorologic factors, nor are the data published as widely.
