Classification of annual rainfall and the rainy quarter of the year in the Paraíba river basin using Rain Anomaly Index (RAI)

Abstract

The Paraíba river basin is very important to the agricultural sector and to the local and regional socio-economy. This study aims at investigating the climatology of the Paraíba river basin including the analysis of the climate variability influence on local precipitation and the study of rainfall space-time variability in the region, using a tool IAC developed by Rooy (1965). Similarity was found between the pattern of precipitation in the region of High Paraíba and Taperoá and sub-basins of the Middle and Low Paraíba. A "turning point" in the distribution of precipitation was found in the region of High Paraíba and Taperoá, which until the 1960s consecutively dry years were observed. In the other hand, similarity in the alternation between dry and wet years was verified over the IAC series for the sub-basins of the Middle and Low Paraíba.