Rio Grande do Sul is one of the largest grain producer states in Brazil, since most of the crops grown in non-irrigated systems, thus making them extremely dependent on the climatic conditions and on the pluviometric regime. This fact has inspired several research studies in the attempt of characterizing the spatial and temporal behavior of the rainfall. The objective of this research was to study the spatial and temporal variation of alpha and beta parameters of the gamma function for the generation of daily rainfall data in the state. The pluviometric precipitation data were obtained from the National Water Agency (ANA). The modeling of the daily rainfall was divided into the events of occurrence and quantity. Estimation of alpha and beta parameters of the gamma function was accomplished on the basis of historical series followed by the adjustment of these parameters as a function of time and space, and then the comparison between estimated and observed values. According to the results, one can conclude that the proposed methodology can be applied for the generation of synthetic series of daily rainfall in the different pluviometric stations of Rio Grande do Sul.
simulation; rainfall; time series
