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mehran mohamadi; javanshir azizi mobaser; Majid Raoof
Abstract
In order to know the technical status of the irrigation systems and determine the amount of achievement of the objectives of the design stage, it is necessary to evaluate these systems.In this study, 18 classic fixed sprinkler irrigation systems with mobile sprinklers implemented in different parts of ...
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In order to know the technical status of the irrigation systems and determine the amount of achievement of the objectives of the design stage, it is necessary to evaluate these systems.In this study, 18 classic fixed sprinkler irrigation systems with mobile sprinklers implemented in different parts of Ardabil plain in the summer of 2019 were evaluated. For this purpose, criteria such as Christiansen Uniformity Coefficient (CU), Distribution Uniformity (DU), Potential Application Efficiency of Low Quarter (PELQ),and Actual Application Efficiency of Low Quarter(AELQ),were used at both block and system scales.After measurements and collection of the required information, these criteria were calculated. The mean values of the criteria were for the blocks were 83.46%, 74.96%, 68.93% and 67.94%, respectively, and for the systems, they were82.32%, 73.43%, 65.71% and 66.70%, respectively. In addition, Wind Drift Losses (WDEL), Deep Percolation losses (DP) and irrigation adequacy (ADirr) were found to be, 7.95%, 6.97%and 27.08%, respectively. Results and field studies showed that low values of PELQ and AELQ were affected by inappropriate spacing of sprinklers, lower pressure compared to design pressure, high pressure changes in the system and simultaneous use of large number of sprinklers. In addition, inaccurate management in operation, land topography and long lengths of pipes are effective factors in reducing the actual performance indicators of irrigation systems in Ardabil plain. Among the suggested recommendations are a revision of the designs, due consideration of the land slope, change in the type of sprinklers, or even change in the orifice of the sprinklers.