Title: Assessing Sprinkler Irrigation Performance Using Field Evaluations at the Medjerda Lower Valley of Tunisia
Abstract: Irrigation uniformity and wind drift and evaporation losses (WDEL) are major concerns for the design and management of sprinkler irrigation systems under arid or semi-arid conditions.Field trials were carried out to assess irrigation uniformity and WDEL under various wind velocities, sprinkler spacings and operating pressure heads.Based on experimental data, a frequency analysis was performed to infer the occurrence probability of a given uniformity coefficient (UC).In addition, statistical regressions were used to model WDEL as a function of different climatic variables.Increasing the operating pressure head improved uniformity at low wind speeds.It was shown that UC has been severely impaired at wind speeds above 4 m/s.In the prevailing wind conditions, the frequency analysis showed that a sprinkler spacing of 12 m × 12 m provided the best uniformity.In the local conditions, it is recommended to stop irrigation when wind velocity exceeds 4 m/s.Moreover, it was shown that wind speed and relative humidity were the main significant variables influencing WDEL.