Investigating the midpoint of a two‐point method for predicting advance and infiltration in surface irrigation*

Abstract

AbstractThis study used the location of the average advance time (method 1) and the mean infiltration opportunity time (method 2) as the midpoint of the two‐point method for determining “power advance” and Kostiakov–Lewis infiltration parameters. Experiments were carried out in three border‐irrigated fields. The results showed that calibration of the power advance equation obtained by the Elliot and Walker method had high accuracy, with an average relative error of 11.3% in the time to complete the advance phase. The root mean square deviation (dRMS) index used by Elliot and Walker showed that method 1, with an average dRMS value of 15.7 min, has the lowest dRMS, which estimates the advance time with mean dRMS values of 5.1 and 1.8 min less than the proposed method 2 and the method of Elliot and Walker, respectively. Furthermore, using all methods, the Kostiakov–Lewis infiltration equation parameters were determined. In estimating infiltration depth, method 1 had the highest accuracy with a minimum relative error of 0%, a maximum relative error of 8.7%, and an average relative error of 3.8%. Based on both the dRMS index and the accuracy of the infiltration equation, method 1 had a higher accuracy.