ABSTRACT
Accurate estimation of the effects of an agricultural management system or individual practice on the volume and rate of runoff are essential in the evaluation and planning associated with soil and water conservation. Theories and experiments of the rainfall runoff process abound at scales ranging from those at a point which considers the vertical flow of water within the soil profile to those at a watershed which considers the integrated response of the entire watershed occurring at the outlet. Many approaches have been taken into account for the runoff effects on the erosion process, ranging from ignoring the direct effects of runoff, to computing the water flow profile and velocity as it changes in the downslope direction. One of the most widely used methods to compute direct storm runoff is the Soil Conservation Service (SCS) Curve Number method. Conceptual models of infiltration are derived from some sort of formulation of the movement of water through a porous medium.
