Relationships Among Sprinkler Uniformity Measures

In the search for a wholly satisfactory way to characterize the extent to which an overlapped sprinkler irrigation distribution pattern falls short of complete uniformity, an increasing number of methods of measuring the degree of nonuniformity have arisen. Five measures which are varieties of methods for expressing the dispersion of precipitation about the mean over an area are defined and compared herein. Some experimentally determined relationships between pairs of measures are presented graphically, then compared with the linear relationships between them which were theoretically derived from the assumption that the distribution of precipitation in an over-lapped pattern is normal orgaussian. It is found that the plotted points are scattered but they cluster about these lines, although the assumption of normality is invalid.