The design and evaluation of travelling gun irrigation systems: enrolador software

Abstract

Travelling gun irrigation systems offer great mobility and operation flexibility with a low investment cost per unit of irrigated area. However, the drawbacks include high operating pressure, low application efficiency, and high rainfall, runoff and erosion. Many of these problems can be minimized if the design and operation of travelling gun irrigation systems are carried out carefully, taking into account several design criteria that will ensure the quality of the irrigation performed by the system. The Enrolador software was developed to meet this goal. The software designs the travelling gun irrigation system, performs its simulation and its performance evaluation. This software was experimentally applied in the Alentejo region, Portugal. The design flow rates were computed for maize and sunflower crops with the soil water balance model IrrigRotation, considering a probability of non-exceedance of 75%. Meteorological data from the Évora weather station for the years 1961 to 1990 were used. Five plots with 3, 6, 9, 12 and 15 ha were chosen for the design of the irrigation systems using the software. The Enrolador software was used to select the equipment (gun, hose and reel) and the appropriate operating parameters for each plot. This software allows for the selection of the equipment that best meets the design criteria.

Asymmetric Wetted Sector Angle in Water Distribution of Traveling Gun Irrigation Systems

“…The geometric shapes of the transverse profiles of water depth applied by the sprinkler moving along the travel path, for asymmetries greater than 30º with wetted sector angles from 300 to 330º, when overlapping for irrigation strip widths between 30 and 80% of the WD, result in high uniformity coefficient values (CU ≥ 80%). These wetted sector angle adjustments also lead to lower water application rates provided by sector angles close to 360º (Rolim & Teixeira, 2016), but it causes a wetted path along the sprinkler trajectory for rotation angles (β) greater than 15 and 30º, respectively, for wetted angles of 330 and 300º.…”

“…As the water application uniformity of traveler irrigation systems is affected by many factors, a correct combination may provide high values of uniformity, on the other hand, an inappropriate combination may compromise water distribution in the irrigated area by the irrigation system (Hashim et al, 2016;Jangra et al, 2017). Thus, the use of sprinkler simulation models to predict water distribution is an essential tool, when the aim is to optimize the water application uniformity (Rolim & Teixeira, 2016). Keller & Bliesner (1990), considering that gun sprinklers have an almost uniform radial profile, recommend for under very calm wind conditions an irrigation lane spacing of 80 to 90% of the wetted diameter (WD) and sprinkler sector angles from 210 to 240º.…”

Optimal Irrigation Allocation for Large-Scale Arable Farming

“…More specifically, we assume that the agents are mobile and can move over a field to deliver the water. These include, for instance, popular machines such as traveling gun irrigation machines [12], [13].…”

Moved-Lateral, Gun, and Traveler Sprinkler Systems

“…Computer simulation programs have been developed to predict the performance of traveler systems. Programs such as that by Rolim and Teixeira (2016) or Smith et al (2008) can be used to design and evaluate traveler systems and as decision support systems to enhance management. Those resources should be examined for advanced management.…”