Evaluation of Hydraulic Performance of Existing Drippers in Some Trickle Irrigation Systems (Case study: Sides of Zayandehroud River, Chaharmahal and Bakhtiari Province)

Efficiency of a trickle irrigation system depends on the hydraulic performance of drippers and the design criteria. Lack of attention to drippers problems may cause reduction in water distribution uniformity, increasing time of system working, permanent drippers replacing, increasing the cost of system and even system failure and returning to traditional systems. So, in this study, the performances of drippers at three fields including Oman Samani, Fadak and Emamieh at the sides of Zayandehroud river in Chaharmahal and Bakhtiari Province were evaluated.The results showed that indices the of uniformity distribution ofthe Omman Samani, Fadak and Emamiehwere 56.8, 95 and 69.3 percents respectively. The discharge variations of drippers of Omman Samani, Emamieh fields were mainly due to undesirable pressure, clogging of drippers and replacing existing drippers by non-expertized farmers. The hydraulic coefficients of variations of drippers at Omman Samani, Emamieh andFadak fields were obtained with the values of 43.7, 28.2 and 6.3, respectively that showed an unsuitable hydraulic design of the first two fields and a proper design of the last one. overall, the performances of Micro Flapper and Dripper emitters at the Omman Samani and Emamieh fields were undesirable and the Netafim one at the Fadak field had an excellent performance.