Exploring geotechnical risk assessment in flood-prone regions: lessons from the 2024 climate disaster in Rio Grande do Sul, Brazil

Abstract

This article reviews geotechnical risk management theories applied to flood scenarios, focusing on the flooding of Rio Grande do Sul in 2024. The research addresses the definition of geotechnical risk, including the concepts of danger, vulnerability, exposure, and consequences. Qualitative and quantitative risk analysis methodologies are explored, such as Failure Mode and Effect Analysis, Fault Tree Analysis, and probabilistic methods, with an emphasis on application in flood situations. Probabilistic modeling, using stochastic models and Monte Carlo simulation, is discussed to predict the behavior of soils and structures, in addition to sensitivity analyses of geotechnical variables. The geotechnical impact of failures during floods, such as landslides and foundation collapses, is assessed, considering the quantification of material and economic damages. Mitigation strategies are presented, including preventive planning, strengthening infrastructure, and increasing the resilience of structures. This research advances geotechnical risk management by establishing an integrated probability-consequence framework that synthesizes qualitative, quantitative, and socioeconomic assessment methodologies. Validated through the 2024 Rio Grande do Sul floods, this approach offers actionable protocols for enhancing infrastructure resilience in flood-prone regions, particularly under climate change intensification.