Modelagem hidrodinâmica e análise geoespacial aplicadas à avaliação do risco de ruptura de barragens: estudo de caso da barragem de Galego, Sabará - MG

Abstract

The growing urban expansion in areas adjacent to mining tailings dams creates a critical scenario, in which challenges related to structural safety, socio-environmental vulnerabilities and territorial planning converge. This is because the disorderly occupation in such areas intensifies the exposure of populations and infrastructures to high-risk zones, compromising the capacity to respond to rupture events and socio-environmental resilience. Based on this, this research has as its object of study the Galego dam, located in the municipality of Sabará, Minas Gerais, and aims to evaluate in an integrated manner the risks associated with a possible rupture of the tailings containment structure, as well as the implications of the eventual catastrophe for the sustainable urban territorial planning of the region. For this purpose, high-resolution hydrological and hydrodynamic modeling was used, using the HEC-RAS (Hydrologic Engineering Center - River Analysis System) software, developed by the United States Army, in conjunction with Geographic Information Systems (GIS) and public databases. Based on simulations of failure scenarios, critical parameters such as arrival time of flood mud, maximum depth, flow velocity and extent of the impacted area were analyzed, with special attention to densely populated areas and critical infrastructure, including the BR-381 highway. The results indicate that, in the event of collapse of the containment structure, the consequences would be severe and immediate, with high potential for human, material and environmental losses. This research also included a multitemporal analysis of the dynamics of land use and coverage in the vicinity of the dam between 2012 and 2021, with calculation of the Kappa index to measure the accuracy of the data. In addition, information from the Mapbiomas project for the year 2023 was incorporated, enabling a detailed assessment of recent urban expansion and degradation of native vegetation in the area of influence of the dam under study. The evidence found in this study reveals disorderly urban growth, insufficient land use regulation and the absence of early warning systems for dam failure. Thus, it is concluded that the management of territories under the influence of dams requires a technical and multidisciplinary approach, which integrates predictive modeling tools, geotechnologies and participatory territorial planning. The adoption of preventive measures, such as continuous monitoring systems, definition of buffer zones, strengthening of safety standards and environmental education programs, is imperative to guarantee water security, ecological integrity and the quality of life of exposed populations. In view of all this, scientific research reaffirms the urgency of effective and evidence-based public policies that promote resilience and sustainability in at-risk territories. This study is aligned with the United Nations (UN) 20230 Agenda for Sustainable Development, with a specific focus on the following objectives: SDG 06 (Clean Water and Sanitation), SDG 11 (Sustainable Cities and Communities), SDG 14 (Life Below Water) and SDG 15 (Life on Land), highlighting the relevance of disaster risk management in the context of the 2030 Agenda.