Avaliação dos impactos de eventos extremos na macrodrenagem de Fortaleza/CE

Abstract

The study addresses the impacts of extreme climatic events on the macro-drainage system of Fortaleza, focusing on the Cocó and Maranguapinho rivers. It begins by noting that the Ceará coastline suffers from sea encroachment, driven by global sea-level rise, coastal erosion, and poorly planned human interventions. At the same time, Brazil has experienced a sharp increase in the frequency and intensity of heavy rainfall, leading to floods, inundations, and large-scale social and economic losses. The theoretical framework explores the factors influencing tides, from astronomical aspects to atmospheric and topographic conditions, and the mechanisms behind heavy rainfall, classified by intensity and duration. It also discusses concepts of fluvial hydrodynamics, emphasizing hydrodynamic risk, which relates water depth to flow velocity. Methodologically, the research employs the RAS Alpha software, combined with a high-resolution Digital Terrain Model, to simulate scenarios of sea-level rise and extreme rainfall. Boundary conditions were defined for representative months (January and October), allowing the isolated and combined assessment of tidal and precipitation effects. Results show that marine intrusion into estuaries can significantly alter mangrove configurations and expand flood-prone areas. The study concludes that Fortaleza’s drainage network is not adequately prepared to withstand such transformations, highlighting the urgent need for early warning systems and mitigation measures to reduce social, environmental, and economic vulnerabilities.