Probable Rainfall of Divinópolis City, Minas Gerais State, Brazil

Abstract

The aim of this paper was to analyze the behavior of non-parametric statistical distributions on the prediction of probable monthly and total annual rainfall as well as to determine the monthly and annual probable rainfall with different levels of probability for Divinópolis, Minas Gerais State, Brazil. The analysis consisted in adjusting the theoretical probability distribution to a data series of 66 years of monthly and annual rainfall. The data were obtained from the Hidroweb service, controlled by the National Water Agency (ANA, in Portuguese). The frequency distributions of Gumbel for Maximus, Fréchet and Gamma were adjusted to the observed series, where the adherence of these models to the data were tested by the Kolmogorov-Smirnov and Chi-Squared test, both with 5% of probability. The model that best represented, in most cases, the frequency distributions of the series of total monthly precipitation was Gumbel for Maximus, while the Fréchet model had the worst result, not fitting to the data of the historical series for both tests performed in the study. The probable monthly maximum precipitation for Divinópolis is 527 mm, associated with a probability of 5% and for January, while the lowest one is 0.0042 mm, with probability of 95% in July.