PROBABILITY OF PRECIPITATION OCCURRENCE IN THREE CITIES IN THE ALTO JURUÁ BASIN

Abstract

Precipitation is a water component of extreme importance in several areas, mainly with regard to agriculture. Its study has considerable relevance in order to minimize possible losses, maximize gains, in addition to enabling sustainable management of plantations and water use. The objective was to analyze the distribution of precipitation data in three meteorological stations in the upper Juruá Basin, as well as to evaluate their adjustment to six probability distributions (Log-Normal, Weibull, Gama, Normal, Logistic and Cauchy), considering a period 27 years calculated over periods of 10, 20 and 30 days, at probability levels of 50, 70, 80, 90 and 95%. It was observed that the Normal, Logistic, Cauchy and Weibull distributions showed the best fit for the rainfall data. When adopting the value of 80% of probability, it was possible to notice that in the majority of the evaluated ten years, the average value is below the probability of 80%, which characterizes an undersizing in the dimensioning of irrigation systems. Still considering the probability of 80%, the same situation is observed when evaluating a monthly period.