Abbreviated Sprinkle Irrigation Evaluation

Abstract

ABSTRACT COMPUTER simulation of uniformity and water ap-plication depth as a function of sprinkler spacing along the mainline and lateral was used to study an abbreviated method of evaluating performance of periodic and solid set sprinkle irrigation systems under no-wind conditions. A full-scale two-dimensional grid layout of collectors was abbreviated to 10 collectors equally-spaced between two sprinklers along the lateral. According to the simulations, the abbreviated method can replace full-scale evaluation when mainline spacing is less than 0.65 wetted diameters (0.65 D). This does not exceed the recommended mainline design spacing of 0.65 D suggested in Jensen (1980) for no-wind conditions. Further, since recommended lateral spacing is not to exceed one-half mainline spacing, lateral spacing is at most 0.65/2. Agreement between abreviated and full-scale results applies to lateral spacings in excess of 0.65/2. Although the method shows promise for predicting uniformity, it is less effective for predicting average water application. However, average water application depth can be calculated from sprinkler flow measurement and sprinkler spacing.