Model of Water Application under Pivot Sprinkler. II: Calibration and Results

A distributional semiempirical model for the simulation of spatial distribution of water application under center pivot sprinklers has been developed by the writers. This method describes the probability of water application for a sprinkler using a combination of beta functions. The calibration of this model has been undertaken using laboratory tests conducted in controlled conditions and then in windy conditions. The parameters calibrated are listed. The minimum number of tests needed for calibration has been estimated. The model used can be calibrated from one test in controlled conditions and three or four tests in windy conditions covering the range of usual wind speeds. Validation should be performed using at least two more infield tests. This simulation model of spatial water distribution under sprinklers of center pivot will thereafter be used to simulate the distribution of water under a typical pivot machine.