Avaliação de eventos extremos de precipitação, associados a desastres naturais

Abstract

The present study mainly aimed to make a statistical survey of extreme precipitation events for the eastern region of the Brazilian Northeast, more specifically for the city of Maceió/AL. For this purpose, punctual data from INMET Automatic Meteorological Stations were used, and spatial data using satellite images and hydro-estimator data provided by CPTEC/INPE. The main results were based on daily precipitation data and quantile technique, it generated the following R(mm) classes: Dry Day R < 2.4mm, Drizzle Rain 2.4 ≤ R < 3, 8mm, Showers 3.8 ≤ R < 7.6mm, Moderate Rain 7.6 ≤ R < 14.4mm, Heavy Rain 14.4 ≤ R < 39.8mm, Strong Rain 39.8 ≤ R < 82.8mm, Extreme Rain R ≥ 82.8mm. The method adopted for classifying extreme rainfall (Strong more Extreme) using quartiles proved to be efficient, made by the association between extreme precipitation events and natural disasters using the records of the State of Public Calamity (SPC) degree, that is, the indicators recognition of SPC and annual accumulated average precipitation, point to the possibility of occurrence of hydrometeorological disasters for the city of Maceió/AL. Regarding the spatial distribution of the number of cases of Strong and Extreme, for Alagoas the municipalities with the most recorded occurrences were Japaratinga, Porto de Pedras, Maceió, among others. For the city of Maceió/AL, the region R5 (Ipioca and Pescaria) and R2 were the ones that presented the most cases of rainfall ranging from very strong to extreme.

Effects of extreme phases of El Niño–Southern Oscillation on rainfall extremes in Alagoas, Brazil

“…Information about changes in rainfall patterns is of paramount importance for the development of public management strategies to minimize the consequences of rainfall extremes in the NEB, especially in Alagoas (Silva Junior et al, 2022; Wanderley et al, 2013a, 2013b) and to identify regions at climate risk. In recent studies, particularly those applied to the climatic mesoregions of Alagoas (Lima et al, 2019; Silva et al, 2020; Silva et al, 2021), research has shown that the majority of extreme events in the state coincide with the occurrence of ENSO phases, and when combined with PDO phases, they either increase or decrease (Lyra et al, 2017), although individual extreme cases of ENSO are not specifically highlighted.…”

“…Alagoas is plagued by severe droughts, recurrent floods and flash floods (Costa et al, 2020a(Costa et al, , 2020bLyra et al, 2014Lyra et al, , 2017Oliveira Júnior et al, 2012), despite being one of the states with the smallest territorial area in Brazil (IBGE, 2023). Studying the extreme phases of ENSO is important to understand the impacts on various areas of society, particularly in agriculture and tourism, which are the main economic sectors in Alagoas (Oliveira-Júnior et al, 2021a, 2021bSilva et al, 2020;Da Silva et al, 2021;Souza et al, 2012) and to support the state's Civil Defense (Silva Junior et al, 2022). However, few studies have focused on the effects of extreme ENSO phases and their influence on ENEB, especially in Alagoas, using historical observed time series, with particular attention to the occurrence of Mega El Niño (Wang et al, 2015;Zeng & Sun, 2022).…”

“…The state of Alagoas, located in ENEB, is highly vulnerable to extreme events (Silva Junior et al, 2022), and it also has poor socioeconomic and demographic indicators, particularly in terms of human development index (HDI) and Gini index (Hissa-Teixeira, 2018). Alagoas is plagued by severe droughts, recurrent floods and flash floods (Costa et al, 2020a(Costa et al, , 2020bLyra et al, 2014Lyra et al, , 2017Oliveira Júnior et al, 2012), despite being one of the states with the smallest territorial area in Brazil (IBGE, 2023).…”