TECHNICAL EVALUATION OF IRRIGATION UNIFORMITY IN SOLID SET SPRINKLER SYSTEMS

Solid-set sprinkler irrigation systems are used as a modern irrigation method. Unfortunately due to lack of proper design and performance of the system in several agricultural lands, the efficiency of the Solid-set sprinkler irrigation systems is low or unacceptable. The specific objective of this study is to evaluate of water distribution uniformity of portable sprinkler irrigation systems under field conditions in Miandoab region, West Azarbaijan province at northwest of Iran. For this purpose, 10 solid set sprinkler irrigation systems were selected accidentally and were evaluated in three steps during the irrigation season in 2012 and 2013 in order to the evaluation of distribution uniformity in solid set sprinkler systems. The average of pressure difference percentage is achieved 39.8 percent in irrigation systems that extreme differences are caused in sprinklers discharge. It should be noted that average of pressure difference percentage is exceeded of designed allowed limit in many irrigation systems. So that of 10 irrigation systems evaluated, only 2 cases, the average of pressure difference percentage were below the designed allowed limit of 20 percent. Thus evaluating indicators were used such as Christiansen's Uniformity Coefficient (CU) and Distribution Uniformity (DU). The results showed that the overall average of CU and DU were obtained 59.4 and 46.3% respectively. DU variation related to CU calculated as following equation at irrigation systems. R 2 =0.934