Curve-Number Procedure as Infiltration Method

The soil conservation Service (SCS) curve-number procedure is commonly used to determine rainfall excess. The advantage of this method is that the parameters in the relation are the soil type, land use, and precipitation, each of which is relatively easy to estimate. The method does have some shortcomings. The procedure for analysis of intermittent rainfall and for portions of storms where rainfall intensity is less than infiltration capacity is not well defined. In addition the SCS method predicts that the infiltration rate will approach zero during storms of long duration instead of a constant terminal infiltration rate.