Variabilidade espaço-temporal da precipitação pluvial diária sobre a bacia hidrográfica do açude Epitácio Pessoa.

Abstract

This work consists of a study of the behavior of the daily rainfall occurred, in the state of Paraiba, over the hydrographic basin of the Epitacio Pessoa reservoir. The main objective was to analyze the climatological distribution of the spatial and temporal mean probability of occurrence of the rainy days over the region under study, utilizing the daily rainfall data for the period of 1963 to 1992, of 27 rain gauge stations, distributed evenly in the hydrographic basin. The empirical probabilities were obtained from the total number of rainy days. The topographic maps were generated from the altitude data obtained from the radar measurements. The regionalization of the rainfall data for the hydrographic basin was performed with the annual climatological data utilizing an automatic classification technique of the hierarchical type. The results show that the occurrence of the spatial distribution of the mean precipitation was similar in form, throughout the rainy season and higher empirical probabilities persisted over the cities of Monteiro, Prata, Sume and Taperoa, and can be related to the presence of the meteorological systems, in this area, by the orographic effects. The rainfall regionalization divided the hydrographic basin into three homogeneous regions based on the mean precipitation ± 20% (group 2), group 3 had precipitation values higher than those of group 2 and group 1 had precipitation values lower than those of group 2.