Infiltration and water extraction from trickle irrigation source: the effective hemisphere model.

Infiltration from a point trickle source in the presence of water extraction is investigated using an approximate hemispherical model. Analytic expressions for the position of the wetting front are derived. In the short-time limit the wetting front follows a simple t one third dependence. The rate of advance of the wetting front depends on a single soil parameter, closely related to the saturated water content. At larger times the effects of water extraction modify the solution to an exponential approach to a limiting radius, which is determined by the balance between the competing discharge and extraction processes. -from Authors