Spatial and Seasonal Variability of Rainfall in the Piquiri Watershed - PR

Abstract

 This study presents an analysis of the seasonal and spatial variability of rainfall in Piriqui watershed, located in Paraná State, Brazil. By adopting the standard-year method, we chose 1983, 2001, and 1978 to represent the rainy, regular, and dry years, respectively. The precipitation data used in the experiment were provided by the Paraná Water Institute (Instituto das Águas do Paraná), and the analyzed historical series corresponded to the period between 1976 and 2010. Seventy-three (73) rain gauge stations were used for the research development. The spatial variability of precipitation was mapped for the four seasons of the year (1983, 2001, and 1978), and unique differences were observed in the isohyet pattern and participation of atmospheric dynamics in the spatial distribution of rainfall in the Piriqui watershed. There was a marked increase in precipitation above the average in the fall of the rainy year and also a considerable decrease in the fall of the dry year. Spatially, an isohyet pattern with gradually increasing precipitation towards the south and southeast of the drainage basis is observed in the dry, rainy, and regular seasons of the year