Irrigation & Drainage Systems Engineering

Hydraulics of Linear-Move Sprinkler Irrigation Systems, III: Model Evaluation

Abstract

Zerihun D, Sanchez CA, Thorp KR and Hagler MJ

This is the third manuscript of a three-part paper that presents the development and evaluation of a hydraulic simulation model for linear-move laterals equipped with pressure reducing valve (prvs). System description, model assumptions, and specification of the lateral hydraulic simulation problem are discussed in part-one of the paper. Formulation and numerical solution of the lateral hydraulic simulation problem are described in manuscript-two. Results of model evaluation and simulation examples, showing model applications, are presented here. Measured hydraulic data-sets, consisting of lateral pressure head profiles and inlet discharges, were used in model evaluation. The data was obtained through field tests conducted on a linear-move sprinkler irrigation system fitted with prvs. Comparisons of model-predicted and field-measured lateral pressure head profiles and lateral inlet discharges suggest that model performance is satisfactory. Furthermore, potential applications of the model in analyzing prv-set pressure effects on lateral hydraulics and, possibly, in the selection of a suitable prv-set pressure for a lateral with a given parameter combination is shown using simulation examples.