IDENTIFICAÇÃO DE REGIÕES PLUVIOMÉTRICAS HOMOGÊNEAS NA BACIA HIDROGRÁFICA DO RIO PARANÁ

The aim of this study was to identify and analyze homogeneous rainfall regions in the Parana River basin, through cluster analysis technique. It was used daily data of precipitation from 789 rainfall stations in a period of 31 year (1980-2010). As the spatial distribution of rainfall data is irregular, the data interpolation contributed in filling the data in locations not sampled. The method of ordinary kriging was used, and the exponential model is presented as the most suitable for presenting the smallest errors. From this analysis, it was possible to identify large groups that have similar patterns of rainfall in the study area. The interpolation of the data helped the more detailed definition of homogeneous regions of precipitation, by cluster analysis. Getting eight regions with different precipitation behavior: the southern regions of the basin, have less variation over the months of the year, with peaks in spring and fall, while the regions north and center of the basin, have a well-defined annual cycle, characterized by a dry season in winter and a rainy season in summer.