Assessing sprinkler irrigation uniformity using a ballistic simulation model

Experiments were performed in the Ebro Valley of Spain to provide the basis for the calibration and validation of a ballistic simulation model of sprinkler irrigation. The experiments included evaluations of isolated sprinklers and solid-sets. Two different sprinklers, two principal nozzle diameters and three operating pressures were considered in the experiments, which also covered the usual range of wind speeds in the study area. Model calibration served the objectives of predicting the Christiansen Coefficient of Uniformity (CU) and the water application pattern. The resulting standard error of CU estimation was 3.09%. Tables of simulated uniformity were produced for the two sprinklers using different nozzle diameters, sprinkler spacings, operating pressures and wind speeds. These tables can be used for design and management purposes, identifying options leading to adequate irrigation uniformity. A simple simulation software has been produced and disseminated to assist irrigation professionals and farmers in decision making.