Estimate and probable monthly rain precipitation distribution in the state of Paraná

Abstract

. Estimate and probable monthly rain precipitation in the state of Paraná through daily precipitation data observed in 22 collection sites ranging between 12 and 26 years are analyzed. All the rainfall series were fitted by gamma and lognormal distributions using likelihood method for parameters. The probable precipitation for periods of 30 days with 75% probability level was estimated by both distribution models. The chi-square and Kolmogorov-Smirnov tests, at 5% level of significance, were used to check which of the distributions could better be adjusted to pluviometrical conditions in the state of Paraná. Results show that the range distribution tends to adjust appropriately to the pluviometrical conditions of the state during the studied period. The rainiest months are January and February, while the driest ones are July and August. The state of Paraná presents an increase in the amount of precipitation which is more observed on coast/west and north/south, during the rainiest and driest periods, respectively.