Spatio-Temporal Analysis of Intense Precipitation Events in Rio de Janeiro State

Abstract

The present study aimed at analyzing the intensity and trend of intense precipitations in Rio de Janeiro State, by using daily data taken from 53 pluviometric stations since 50 years ago (1968-2017). Homogeneous regions have been determined based on the monthly average of intense daily rainfall (≥ 95th percentile) being analyzed four climate extreme indicators: maximum annual precipitation in 1 day (Rx1day), simple daily intensity index (SDII), annual total precipitation having daily precipitation ≥ 95th percentile (R95p) and annual total precipitation in wet days (PRCPTOT). For detecting significant statistically trends, it was used the Mann-Kendall test. The magnitude of the trends was obtained by the Sen estimator. The results have shown two homogeneous regions of intense precipitation. Region 2, composed by areas of the Baixadas Litorâneas, southeast of the Metropolitan region and south of North Fluminense, presented more intense rainfall than the other areas of the State (region 1). Region 2 has also presented a larger number of extreme indicators with significant trends (at 95% of confidence level), being in their majority represented by increased precipitation. In SDII, the magnitudes were higher than or equal to +0,16 mm/day/year in Porciúncula, Conceição de Macabu, Cachoeiras de Macacu and Nova Friburgo.

Keywords
homogeneous regions of intense precipitation; climate extreme indicators; trend analysis