The behavior of water uniformity distribution in center pivot irrigation with varied distances

Uniformity of water distribution is one of the most important factors in the evaluation of irrigation systems. The aim of this study was to investigate the uniformity of distribution (CU) and distribution uniformity coefficient (DU) in center pivot irrigation system with different distances of cans in radial direction and to obtain the relationship between these two coefficients. In this regard, three scenarios in the layout arrangement of cans were considered for evaluating the center pivot irrigation system in the Qazvin Megsal Cultivation-Industry. In the first scenario, the distance of 60 cans in a radial direction of 5 meters, in the second scenario, the area under irrigation of the system was divided into 60 equal concentric circles, and the location of each can placed middle of distance of circles, and in the third scenario, 15 cans were spaced 10 meters, 20 second cans The distance of 5 meters and 25 cans was spaced 2 meters in a radial direction. In the first case, all sprinklers were healthy and in the second case, 30 sprinklers was blocked to examine the effect of cans arrangement on CU and DU coefficients. The results showed that in the first case, the CU and DU coefficients for the first scenario were 84.4 and 79 for the second scenario, 83.9 and 74.8 and for the third scenario it was 80.9 and 73.5, respectively, and in the second case The CU and DU coefficients for the first scenario were 75.1 and 65.3, respectively, for the second scenario, 77.8 and 64.8, respectively, for the second scenario 82.8 and 73.7, respectively. It is not possible to use the formulas of the classical sprinkler irrigation method because the cans are weighed. In this study, using the measurements of CU and DU in the center pivot system and as well as the findings of other researchers, a linear regression relationship with a coefficient of 0.89 between CU and DU in irrigation was obtained. . Using this relationship, we can reduce the volume of Du calculations in irrigation.