Estudo de precipitação diária: regimes pluviométricos e modelos de distribuição para a região cacaueira do sudeste da Bahia.

Abstract

In this work, daily precipitation data collected at 17 stations of the CEPLAC Agrometeorological Network were used, located between 12º 30'S and 19º 33'S latitude and 38º 2 9 'W and 40º 40'W longitude. The historical series covered the period 1964-1982, complete or not, for each season. The pluviometric regimes of these stations were plotted after the classification of the daily data, according to pluviometric scales, in class frequencies. Five different rainfall patterns were delimited, the first for the FZOPALMA and ESOMI stations, the second for FZCULTROSA, EMARC, CEPEC and SEUNA, the third for EGREB and ESPAB, the fourth for GANDU and IPIAfl and the fifth for ITAPEBI, GUARATINGA, ITAMARAJU, FZMARTINICA, ESFIP and FZBESPER. The EZITAJU station presented behavior of both the fourth and fifth regimes. The maximum and minimum number of days with precipitation was in February and August, respectively. The average annual total number of days with rainfall increases with increasing latitude and longitude with small peaks at coastal stations. It was observed that the maximum number of days with precipitation greater than or equal to 60mm was found in December. Theoretical curves were adjusted to the empirical curves referring to the accumulated average monthly class frequencies. The first order Markov chain process was used to calculate the probabilities of dry and rainy days, as well as possible transitions. Rainy days were considered to be those with precipitation greater than 0.5 mm.