Probability distribution and time movements of precipitation in Telêmaco Borba, Paraná, Brazil

Abstract

Had to aim in this work to determine the parameters of five statistical probability density functions (pdf´s) adjusted to decennial values of precipitation (P), determining their probable values at 75% probability, validate functional relationships between average and probable rainfall and perform the decomposition of these time series in Telêmaco Borba, Parana State. To check the adjustment of pdf’s to data series were applied Kolmogorov-Smirnov test at 5% probability. The time series were decomposed to obtain trend (T), cyclicality (C), seasonality (S) and irregularity (I) patterns, through the methods of moving averages, trend component removal and reason for the mobile average, respectively. The pdf’s Gamma and Exponential showed better fit to decennial P, and the other pdf’s were important for obtaining the probable values for the remaining periods of ten days of the year. The estimated P75% from the average rainfall is possible, confirming the existence of a functional relationship between two variables. The daily and ten-day P series didn’t follow any pattern in frequency distribution, characterizing randomness, being influenced by seasonal, cyclical and irregular movements, with seasonality having little influence.