Avaliação espacial e sazonal da precipitação no estado do Pará

Abstract

The objective of this study was to evaluate the spatial variability and seasonal rainfall in the State of Para. Were used monthly data and annual rainfall of 66 rainfall stations available in hydrometeorological network of National Water Agency – ANA for the period 1982 - 2011. The data were organized with the help of Microsoft Excel spreadsheets. The historical series that fail, these were corrected and consisted. Para is the second largest Brazilian state holds great extent and diversity of natural resources. In terms of density, the state, as well as the seven river basin showed low density of rainfall stations do not comply with the recommendations of the WMO as the minimum density of rain gauges, are areas that require better monitoring. As for seasonality, precipitation shows two distinct seasons, a drought (winter and spring in the Southern Hemisphere), with rainfall less than 100 mm, and a rainy season (summer and autumn in the Southern Hemisphere) with rainfall exceeding 200 mm. The results obtained by the Mann - Kendall and Spearman did not detect any trend of increase or decrease in rainfall during the study period. Through cluster analysis of monthly precipitation were defined 3 Homogeneous Regions with similar climatic characteristics (R1, R2 and R3) to the state of Para.