USING ROTATING SPRINKLER GUNS IN CENTRE‐PIVOT IRRIGATION SYSTEMS †

The use of centre-pivot irrigation systems has significantly increased in the last few decades, since they are easier and less time-consuming to manage compared to other irrigation systems. Standard high-pressure impact sprinklers, low-pressure spray sprinklers or LEPA (Low Energy Precision Application) systems are usually combined with a centre-pivot irrigation system (CP-SYS). However, when applying waste water or with reclaimed effluents that are extremely dirty, small nozzle sizes that require CP-SYS could get plugged. As an alternative to common centre-pivot irrigation systems, this paper analyses the ‘geometry’ of areas irrigated by rotating sprinkler guns in a centre-pivot irrigation system (CP-RoSYS), which provide a solution to the plugging phenomena, due to larger-sized nozzles. Overlapping irrigated areas along the tangential and radial lateral directions, i.e. for multiple sprinkler guns, are studied. According to two parameters defining the geometry of the centre-pivot system, simple relationships of the radius of throw along the laterals are derived. The hydraulics and the efficiency analysis of the centre-pivot system, coupled with rotating sprinkler guns, were not examined in this study, but the results could be useful for studying the water distribution uniformity, hydraulic behaviour and efficiency of CP-RoSYS compared with other types of irrigation systems.