Simulação da uniformidade da irrigação de sistemas convencionais de aspersão operando sob diferentes condições de vento

Abstract

The water application uniformity is an important factor to be considered on the sprinkler irrigation system evaluation. Solid set sprinkler system water application uniformity depends on factors such as: sprinkler type and its operational conditions, sprinkler disposition and spacing on the field, and wind velocity and direction during water application periods. Considering that the complex relationships among these factors and uniformity are more efficiently characterized by employing mathematical modeling, this study aimed to evaluate simulations, provided by the RICHARDS & WEATHERHEAD (1993) semi-empirical model of the spatial distribution of the water applied by a PLONA RL-250 gun type sprinkler operating under different wind conditions. Values of Christiansen coefficient of uniformity (CUC) based on in-field single sprinkler tests were compared to simulated values showing, through different evaluation indices (R2=0.73; a 4.1% average absolute deviation, and a 0.78 performance index), that the evaluated semi-empirical model provides reliable estimates of CUC of solid set sprinkler systems. It is demonstrated that mathematical simulations can provide reduction on both the effort and the time required to perform field work related to spatial water distribution evaluations of single gun type sprinklers operating under windy conditions.