Caracterização dos eventos meteorológicos que deflagraram desastres naturais nos estados de Minas Gerais e Bahia: estudo de caso

Abstract

Natural disasters manifest as a result of the conflicting interaction between extreme natural phenomena and vulnerable communities. These phenomena, within the context of climate change, tend to occur more frequently worldwide, especially those related to climatological and meteorological events. In Brazil, there is an extensive history of extreme rainfall events triggering natural disasters. According to the National Institute of Meteorology (INMET), December 2021 was the rainiest month in the last 15 years in northern Minas Gerais and southern Bahia. Some meteorological stations recorded rainfall records, such as the Lençóis–BA station, which recorded 578 mm between December 1st and 27th, 445.4 mm above the climatological average. The heavy rains left approximately 86,000 and 30,000 people displaced in Bahia and Minas Gerais, respectively. In this context, this study aims to analyze, in addition to the history of natural disasters in Minas Gerais and Bahia, the meteorological patterns and associated consequences of the natural disasters that occurred in northern Minas Gerais and southern Bahia on December 23rd, 24th, 25th, and 26th, 2021. Data on natural disasters, satellite images, soil moisture, reanalysis, precipitation from rain gauge stations, and satellites were used. Based on this data, the disaster history of Minas Gerais and Bahia, the meteorological characteristics of the event that occurred in December 2021, and the calculation of return period were analyzed. Regarding the event between December 23rd and 26th, 2021, the phenomenon that triggered the occurrences was the South Atlantic Convergence Zone (SACZ). However, since the beginning of the month, the region has recorded high rainfall accumulations. Regarding the return period, it was observed that only in Unaí–MG did the recorded rainfall exceed what is expected every 100 years. Thus, it is evident the importance of knowing the local characteristics and historical precipitation to classify an event as extreme, as well as highlighting the importance of the public sector in mitigating and reducing the damage from natural disasters.