Dimensionless advance curves for infiltration families

Abstract

Dimensionless advance curves of border irrigation have been developed for Soil Conservation Service (SCS) infiltration families. The volume balance equation was nondimensionally formulated and then used to plot a dimensionless advance curve for each infiltration family that is a function of the exponent a in the infiltration power function and the dimensionless time t*. Initially, the SCS infiltration formula was fitted into a power function. The equivalent parameters for each SCS infiltration family were obtained through a nonlinear regression analysis. The dimensionless curves for a given inflow rate, slope, and roughness coefficient can be used to determine either advance distance at a particular time or time of advance for a certain distance through a few simple steps. The curves also allow reviewing the advance trend of each infiltration family for a sufficiently wide range of dimensionless time covering any condition of dimensioned input parameters. It is anticipated that the curves will help in designing, evaluating, and managing irrigation borders. The more complex zero inertia model has also been used to enhance results of obtained dimensionless advance curves and of fitted SCS infiltration parameters.