Real‐Time Estimation of Furrow Infiltration

Abstract

An analysis to determine infiltration parameters from the early stages of furrow advance is reported. The analysis uses a kinematic‐wave simulation model in conjunction with a simplex search procedure to minimize the differences between measured and predicted advance rates. The technique uses a variable and expanding data set to forecast advance times and is therefore a useful prelude to real‐time feedback control systems for the future automation of furrow irrigation systems. Results from four furrow evaluations involving a sandy loam and a silty clay loam are given to demonstrate the capability of the analysis. The analysis was first verified by using the complete advance data sets for the evaluations. The analysis yielded the same values of the three Kostiakov‐Lewis infiltration parameters found in independent field measurement. In a second investigation, the basic intake‐rate parameter in the Kostiakov‐Lewis function was fixed and the analysis was repeated with advance data from the early stages of advance to determine if and how soon the analysis would estimate reasonably accurate values of the other two infiltration parameters. The results indicate that infiltration parameters can be estimated with sufficient accuracy from early advance data to allow an accurate forecast of efficiency and uniformity at the end of the irrigation.