نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Determining water consumption management indicators in order to select irrigation methods with the highest efficiency is one of the most important strategies for large-scale planning for optimal water use in any country. In this study, the effect of five different management methods of border irrigation was evaluated on improving irrigation efficiency with the goal of increasing alfalfa production. The experimental field included five test plots: A, B, C, D and E, where the respective irrigation methods applied were traditional open-end border irrigation as the control, cut-back (flow reduction) border irrigation with open-end, cut-back border irrigation with closed-end, surge (wave) border irrigation with 5 pulses open-end, and surge border irrigation with 3 pulses open-end. The average reduction of applied water in treatments B, C, D, and E compared to the control (A) were 99, 73, 151, and 11 cubic meters of water per hectare, respectively. Applying methods B, C, D, and E also led to an increase in water advance speed by 20%, 16%, 24%, and 12.5%, respectively, compared to traditional irrigation, resulting in improved uniformity water distribution along the borders and reduced surface runoff losses. The percentage of surface runoff in management methods E, D, C, B, and A was determined to be 31, 27, 0, 14, and 18, respectively, and the percentage of deep percolation losses in these methods was 27, 32, 35, 14.27, and 14.68, respectively. Furthermore, the irrigation efficiency in methods E, D, C, B, and A was calculated to be 45%, 55%, 67%, 71%, and 73%, respectively. The use of 3-pulse surge, 5-pulse surge, cut-back with closed-end, and cut-back with open-end were more effective in water saving and increasing the irrigation efficiency compared to the traditional irrigation method. Meanwhile, the cut-back method with closed-end despite having zero surface runoff, exhibited the highest deep percolation losses. On the other hand, Surge methods had the lowest water losses, with the 5-pulse method showing the least surface runoff. Furthermore, the efficiency of the two models, Surface and WinSrfr, was compared in simulating the hydraulics of each method and estimating water application efficiency. The error of the average water application efficiency calculated by the Surface and WinSrfr models, compared to the average field values, was found to be 1.6 and 0.21, respectively, indicating the higher accuracy of the WinSrfr model under this studied conditions.
کلیدواژهها English