Development of an automatic test bench to assess sprinkler irrigation uniformity in different wind conditions

Abstract

In sprinkler irrigation the water distribution uniformity in field conditions is not always a known factor, mainly due to the many variables involved, especially the wind. The main objective of this study was to design, install and test an automatic sprinkler bench to measure the irrigation uniformity of solid set systems for multiple wind conditions in real time. The system developed measures the different wind speeds and directions while simultaneously recording the rainfall distribution automatically. Consequently, the system requires little manual intervention, thus reducing the operating costs. All the information generated is stored in a database, obtaining multiple results of irrigation uniformity for each stable wind regime. As a second step, uniformities in different situations (layouts and wind directions) were studied. In addition, this study shows the potential for assessing the influence of different variables on irrigation uniformity for several sets of sprinklers. As an example of possible applications, 12,150 results of uniformity coefficients for conventional impact rotary head sprinklers with hexagonal nozzles in windy conditions were generated. These data were used to establish comparisons between different sprinklers. To do this, a multiple linear regression methodology was applied in order to analyse the influence of the different contour variables on the irrigation uniformity. The test bench presented along with the methodology to simulate and generate multiple scenarios constitutes a powerful tool for designers, farmers and technicians both for the improvement of existing installations and for future designs. The generation of a large amount of irrigation uniformity results for sprinkler irrigation in different wind conditions will lead to a large database with the potential to be able to determine the irrigation uniformity in all common scenarios.