Analysis of Colombian Precipitation to Estimate Irrigation Requirements
Monthly and annual distributions of precipitation were analyzed for a 103-year record station. A gamma probability distribution with maximum likelihood estimates of the parameters gave the best fit. For 97 stations throughout Colombia a computer program was written to calculate 13 probability levels of precipitation using the gamma distribution. Potential evapotranspiration was calculated from climatic data at 43 of these stations using the Christiansen and Hargreaves formula. The difference between potential evapotranspiration and five probability levels of precipitation were calculated as an index of irrigation requirements.
Hardee, James E., "Analysis of Colombian Precipitation to Estimate Irrigation Requirements" (1971). Reports. Paper 448.