A Dynamic Model for Water Distribution Pattern of Center Pivot Irrigation System

Document Type : Research Paper

Authors

Abstract

In order to evaluate performance of the center pivot irrigation systems, an understanding of water
application characteristics of these systems is necessary. A new model and its computer program are
developed to calculate applied water depth and coefficient of application uniformity of center pivot
systems. The model uses water distribution pattern of stationary single spray nozzle as an input and
simulates center pivot overall water distribution pattern. For this purpose, two static and dynamic
square grids are considered. The static grid is obtained by dividing irrigated field to square
components. The dynamic grid is resulted from adapting a grid with square components on water
distribution pattern of single spray nozzle and is moved with moving spray nozzle on the center pivot
lateral. Dynamic grid is moved over static grid. Water depths received in the field are determined in
static grid components via considering water applications rates in dynamic components. Distribution
patterns are overlapped in areas covered by adjacent spray nozzles. The model outputs are water
depths received in the field in all components of the static grid and water application uniformity
coefficient. In order to evaluate and validate the model performance, several experiments were
conducted in the field and the model was run for the same conditions. The results showed high
accuracy of the model in simulating water distribution patterns of the center pivot irrigation systems.

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Main Subjects


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