Supplemental Irrigation Storage Reliability

A computer simulation model is used to evaluate the risk of having insufficient water for supplemental irrigation. The model simulates the daily operations of a system consisting of a watershed, pond, and irrigation plot. Daily precipitation and temperature data, which drives the hydrologic functions, is readily obtained from National Weather Service archives. At least 25 years of data is used to determine the frequency of failure of the storage pond to deliver water when there is an irrigation demand. Generalized system reliability curves are generated for moisture deficits ranging from 219-582 mm (8.6-22.9 in.) at five locations in Kansas. The model is useful for designing an individual system or for establishing design guidelines for a region.