Explicit Sprinkler Irrigation Uniformity: Efficiency Model

The relationship between pattern uniformity and application efficiency under a sprinkler irrigation system in which the pattern is assumed to be normally distributed over an area of uniform soil moisture depletion is expressed mathematically. Empirical equations relating the pattern’s coefficient of variation, the fraction of adequately irrigated area, and the ratio of the mean required depth and to the mean applied depth are summarized. The mathematical model is an aid in evaluating the performance of a sprinkler irrigation system on the basis of potential yield reductions over inadequately watered areas, the economic trade-off between the system’s water application uniformity and its cost, and the environmental impacts of excessive drainage. Given criteria for assessing a sprinkler irrigation system in the general sense, the model allows design and operational optimization under widely differing conditions.