Deadly disasters in southeastern South America: flash floods and landslides of February 2022 in Petrópolis, Rio de Janeiro

On 15 February 2022, the city of Petrópolis in the highlands of the state of Rio de Janeiro, Brazil, received an unusually high volume of rain within 3 h (258 mm), generated by a strongly invigorated mesoscale convective system. It resulted in flash floods and subsequent landslides that caused the deadliest landslide disaster recorded in Petrópolis, with 231 fatalities. In this paper, we analyzed the root causes and the key triggering factors of this landslide disaster by assessing the spatial relationship of landslide occurrence with various environmental factors. Rainfall data were retrieved from 1977 to 2022 (a combination of ground weather stations and the Climate Hazards Group InfraRed Precipitation – CHIRPS). Remotely sensed data were used to map the landslide scars, soil moisture, terrain attributes, line-of-sight displacement (land surface deformation), and urban sprawling (1985–2020). The results showed that the average monthly rainfall for February 2022 was 200 mm, the heaviest recorded in Petrópolis since 1932. Heavy rainfall was also recorded mostly in regions where the landslide occurred, according to analyses of the rainfall spatial distribution. As for terrain, 23 % of slopes between 45–60∘ had landslide occurrences and east-facing slopes appeared to be the most conducive for landslides as they recorded landslide occurrences of about 9 % to 11 %. Regarding the soil moisture, higher variability was found in the lower altitude (842 m) where the residential area is concentrated. Based on our land deformation assessment, the area is geologically stable, and the landslide occurred only in the thin layer at the surface. Out of the 1700 buildings found in the region of interest, 1021 are on the slope between 20 to 45∘ and about 60 houses were directly affected by the landslides. As such, we conclude that the heavy rainfall was not the only cause responsible for the catastrophic event of 15 February 2022; a combination of unplanned urban growth on slopes between 45–60∘, removal of vegetation, and the absence of inspection were also expressive driving forces of this disaster.</p

Radiação fotossinteticamente ativa incidente e Refletida acima e abaixo do dossel de floresta de Mata Atlântica em Coruripe, Alagoas

The study of solar radiation is important to understand the several physical, chemical and biological processes that occur in the biosphere, particularly in the forest. The objective of this study has been to evaluate the temporal evolution of incident and reflected Photosynthetic Active Radiation (PAR) above and below the canopy of the Mata Atlantica forest. The study has been conducted in a Private Reserve Natural Heritage, located in the Coruripe city, Alagoas, during the period from October 2009 to September 2010, based on the PAR (2, 13, 26 m) observations obtained at the micrometeorological station, installed on a 24 meters high tower (10° 17' 36"S, 36° 17' 24"W, 160 m asl). According to the results the incident and reflected PAR outside (PAR↓_Ext and PAR↑_Ext) and inside (PAR↑_Spf) forest follow the seasonality imposed by the apparent motion of the Sun. The higher PAR values occur during the dry season, exceeding 600 and 12 W m-2, and during the wet season these averages was less than 300 and 8.0 W m-2, influenced by cloudiness. At the beginning and ending of sunlight time PAR↑_Spf values near zero were measured. The opposite measurements of about 14 W m-2, around 12 h (November and December) were observed

Modelo para amostragem e avaliação de gases de efeito estufa (GEE) em reservatórios com produção aquícola.

Resumo: Este trabalho tem como objetivo a abordagem do protocolo para amostragem e determinação de fluxo de gases de efeito estufa GEE na interface água-atmosfera e concentração de GEE dissolvidos na água para aplicação em corpos d?água com produção aquícola. A metodologia apresentada neste trabalho é sugerida em razão do fácil manuseio, obtenção de dados confiáveis e utilização de equipamentos de baixo custo quando comparada com outras metodologias.bitstream/item/195084/1/DOCUMENTO-116-Paula-Packer-corrigido.pd