A comprehensive study analyzing over 60,000 records of hydrogeological disasters across Brazil from 1991 to 2024 reveals the alarming frequency and severity of extreme weather events, underscoring critical challenges for disaster management and public policy. The research, led by scientists from CEMADEN, the University of São Paulo, and INPE, aims to provide a scientific foundation for developing strategies to prevent, adapt to, and mitigate these socio-natural disasters — events exacerbated not only by climate change but also by governance shortcomings.
Floods, waterlogging, flash floods, landslides, storms, and droughts are pervasive nationwide, with 91.5% of Brazil’s 5,570 municipalities reporting at least one such disaster. Notably, 1,814 cities faced incidents linked to three or more of these factors, and 270 cities suffered from all six. Regionally, the Northeast bore the brunt in terms of affected municipalities, followed by the Southeast, South, North, and Midwest. Fatalities and economic consequences vary geographically, with the Southeast experiencing the most deaths from floods and landslides, the South most storm fatalities, and the Northeast the highest drought-related mortality.
The study highlights critical distinctions among disaster types: flooding stems from river overflow; waterlogging results from overwhelmed drainage systems; and flash floods occur due to intense rainfall over short periods. Economic damages, inclusive of direct property loss and indirect economic disruptions, are most severe in the South for floods and flash floods, the Northeast for landslides and droughts, and the Southeast for storms. Historical events illustrate these impacts vividly: in São Sebastião, São Paulo, record rainfall during Carnival 2023 caused over 60 deaths and infrastructural collapse, while catastrophic storms in Rio Grande do Sul in May 2024 affected 2.3 million people and caused more than 180 fatalities.
Despite Brazil’s recent advances in disaster data collection through platforms like S2iD and the Digital Atlas of Disasters, the study notes critical limitations. Data are self-reported by municipalities seeking federal aid, which can lead to underreporting where local agencies manage events autonomously or lack reporting infrastructure. Approximately 1,660 municipalities reportedly lack organized civil defense agencies, and many existing bodies need professionalization and resources to effectively respond to climate risks. Additional data gaps include the absence of multi-risk recording—events triggered by one disaster type often overshadow linked phenomena—and inaccuracies in attributing causes of death.
Efforts are underway to upgrade disaster databases. SEDEC’s forthcoming revisions to the S2iD platform and Disaster Atlas will adopt multi-risk frameworks and enable disaggregated data collection by age and gender, facilitating targeted responses. These enhancements, paired with technical training for local disaster managers, aim to improve data reliability and narrow disparities among civil defense agencies across Brazil.
Experts emphasize shifting focus from disaster response to proactive loss reduction. Sociologist Victor Marchezini, co-author of the study, stresses that these disasters reflect a chronic crisis intertwined with socioenvironmental vulnerabilities rather than isolated incidents. “We must move beyond accepting economic losses as inevitable,” he says, urging investment in mechanisms that reduce impacts rather than relying primarily on reconstruction efforts.
The research further integrates models predicting urban expansion, land use changes, and hydrodynamics, offering novel geographic risk assessments for flooding in urban areas driven by extreme rainfall. This fusion of climate science and urban planning provides critical tools for identifying high-risk zones within cities, informing more precise and effective mitigation policies.
By illuminating the profound intersection of climate dynamics and social management failures, this study calls for a scientific approach to disaster preparedness and public policy reform in Brazil—transforming data into decisive action to safeguard vulnerable populations and national resilience in the face of escalating extreme weather events.
Subject of Research: Hydrogeological disasters and their impacts in Brazil from 1991 to 2024
Article Title: Water-related disasters in Brazil: an assessment from 1991 to 2024
News Publication Date: 10-Apr-2026
Web References: https://iopscience.iop.org/article/10.1088/1748-9326/ae5991
Keywords: Floods, Climate change, Public policy, Natural disasters, Drought, Landslides, Storms
