IDENTIFICAÇÃO DE TENDÊNCIAS NAS SÉRIES TEMPORAIS DE PRECIPITAÇÃO NA MICRORREGIÃO DO ALTO SERTÃO PARAIBANO

Abstract

The development of the semi-arid region of Northeast Brazil (NEB), mainly in the State of Paraiba , is strongly dependent on its rainfall index. Precipitation variations can cause economic and social damage to the population of the state. The activities of agriculture and breeding, as well as the human supply, are of great importance in the economics of the NEB, and, in particular, for the microregion of the Alto Sertao Paraibano. This study promotes the exploration of the Alto Sertao Paraibano microregion pluviometric time series characteristics, with the objective of investigating circumstantial changes in the precipitation distribution. For the identification of trends in time series of precipitation, the non-parametric methods of Mann-Kendall and Pettitt and the parametric method of Linear Regression were applied to 15 rain stations. At the data organization, it was possible to notice that the microregion rainy season, composed of the months of February to May, is responsible for more than 70% of the total annual precipitation, thus having a graphical oscillation consistent with the yearly average precipitation distribution. The trend identification methods were efficient and comprehensible in time series analysis of rainfall. Both analysis of annual rainfall and the rainy season, although with signs of positive and negative trends, did not become significant. The dry season shows a negative trend in the first ten years studied, but there is no evidence of a recent significant trend.