Nonuniform Sprinkler Irrigation Application Efficiency

Universal relationships between application efficiency, statistical properties of water distribution pattern, and the application ratio are developed assuming that the application depths observe gamma distribution when asymmetrically distributed and normal in the symmetric case. Results for the positively skewed gamma distribution and the normal distribution are extrapolated to treat the negatively skewed applications. These relationships agree with those obtained numerically by other authors from observed distribution patterns. Application efficiency is shown to increase with positive asymmetry for minimum application depths equal to or less than the average depth. Negative asymmetry and larger applications have the oppositive effect on application efficiency. The results are presented in standard units that permit ready evaluation of application efficiency and other parameters for various irrigation systems having different uniformity characteristics.