Furrow infiltration estimation from time to a single advance point

A simple and quick method to determine the Soil Conservation Service (SCS) intake function in furrow irrigation is presented. The time of advance at only one location of the field, inflow rate, and average flow area are the only field data required to estimate the two parameters of the SCS infiltration equation. The dependence of the two intake parameters, k and α, of the SCS intake function was expressed analytically and then the single unknown intake parameter of the SCS function, α, could be determined by applying a volume–balance (VB) equation using a power advance assumption. Estimates of infiltration by the proposed method were compared with measured furrow infiltration data and a recently developed one-point method which uses the two parameter Philip infiltration equation, but is restricted by an assumption that the advance trajectory follows the power function with the exponent of 1/2. It is shown that the proposed one-point method can give more accurate results than the previous one-point method.