Soil moisture velocity equation

The soil moisture velocity equation describes the speed that water moves vertically through unsaturated soil under the combined actions of gravity and capillarity, a process known as infiltration. The equation is alternative form of the Richardson/Richards' equation. The key difference being that the dependent variable is the position of the wetting front , which is a function of time, the water content and media properties. The soil moisture velocity equation consists of two terms. The first "advection-like" term was developed to simulate surface infiltration and was extended to the water table, which was verified using data collected in a column experimental that was patterned after the famous experiment by Childs & Poulovassilis (1962) and against exact solutions.

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