The western region of Paraná state, covering the Paraná III Basin, has an agricultural system still largely dependent on climatic conditions. Thus, the aspects that involve the construction of probabilistic models, able to determine parameters of occurrence and quantification of the daily precipitation have emerged as a necessary and fundamental factor for the achievement of regional projects in all areas. Therefore, the objective of this work was the construction of such models considering the occurrence of ENSO phenomena, using for this purpose data from 34 weather stations with series of more than 21 years of daily records, which were obtained from the ANA (Agência Nacional de Água). The modeling of the occurrence of daily precipitation was treated through the Markov processes, while the modeling of the precipitated amount was performed by adjustment of the gamma function of probability. For validation of the adjustment, the Kolmogorov-Smirnov test was used. From the results it was established that this methodology can be applied to the simulation of synthetic series of daily rainfall for the study area.
water resources; synthetics series; gamma probability distribution
