Analysis of Trends in Extreme Precipitation in the State of Minas Gerais

Análise das Tendências de Precipitação Extrema no Estado de Minas Gerais

Abstract

The study of the behavior of intense precipitation is extremely important in the management of disasters triggered by these events that culminate in environmental, social and economic damage throughout Brazil. The main objective of this work was to identify the trends and behavior of intense precipitation events in the State of Minas Gerais. Daily precipitation data from 309 rainfall stations managed by the National Water and Basic Sanitation Agency (ANA) were analyzed, corresponding to the period between 1978 and 2017. The quantile technique was used as a confidence interval (95%) in the trend analysis. The Mann-Kendall Test and the Sen Estimator estimated the trends and their magnitudes, respectively. Of the 309 stations analyzed, 20 stations showed a statistically significant trend (at the 95% level) in the intensity of events, with 8 stations showing an increasing trend and 12 stations showing a decreasing trend, in the States of Minas Gerais. Summer recorded the highest rate of intense rainfall (≥ 50%) throughout the State. An increase in extreme rain events was observed in some points in the north of Minas (increase of 0.20 mm/day/year) and a reduction in the Triângulo Mineiro region and central strip of Minas Gerais (reduction of 0.1 mm /day/year).

Keywords
extreme events; mann-kendall; magnitude