High distribution uniformities and efficiencies can be achieved when hydraulic design produces the pressure required for the selected sprinkler discharge, with acceptable variation within the system, and when the layout design is based on optimal sprinkler spacings. The design of the system layout, including the selection of sprinklers and respective spacings is dealt with in several publications [11, 94, 96, 98, 99], as are the hydraulics of sprinkler systems [11, 96, 106-109]. Several engineering standards also support appropriate design (ASAE S261.7, S263.3, S376.1, S394, S395) .
Uniformity [DUor CU, Eq. (5.119) and (5.120)] resulting from adjacent sprinklers can be estimated by simulation of the overlap of four adjacent sprinklers in a rectangle, or three in the case of a triangle. The effect of wind can be considered by changing the original circular pattern into an ellipse with radii that vary with the wind speed .
The design also should aim at achieving high efficiencies. Considering that the application efficiency depends upon the uniformity, Keller and Bliesner  propose to compute the distribution efficiency DEPa (%) corresponding to a desired percentage pa of the irrigated area receiving the target irrigation depth (or area adequately irrigated):
DEPa = 100 + (606 - 24.9pa + 0.349(pa)2 - 0.00186(pa)3)( 1 - — ), (5.150)
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