PERFORMANCE OF IRRIGATION SYSTEMS IN SOUTH AFRICA - Management, Performance, and Applications of Micro Irrigation Systems - page 64

FIGURE 2 Performance of impact sprinkler systems.

Results in this study indicated that the coeffi cient of uniformity (CU) was 72%
for the dragline, 74% for the fl oppy and 89% for the center pivot systems, with the
accepted norm of 84% or higher. The emission uniformity (EU) for the micro and
drip systems was 72% with the norm of 92% and higher. The average low quarter
distribution uniformity (DU) was 60% for the dragline, 67% for the fl oppy, 83%
for the center pivot and 68% for the micro and drip, respectively, with the accepted
norm of 75% and higher. The average application effi ciency (AE) was 76% for the
dragline, 77% for the fl oppy and 82% for the center pivot. The statistical uniformity
(SU) for the micro and drip systems was 74% with the accepted norm of 90% or
higher.
The Tables 2 and 3 show the percentage of irrigation systems that comply with
the norms. It can be observed that only a small amount of center pivot, fl oppy and
micro systems had been tested and it might not be a true statistical refl ection of the
performance of these systems in the different areas. All the center pivots had an
excellent CU and DU and none of the fl oppy irrigation systems exceeded the CU or
DU norm.