Modelagem hidrológica e hidrodinâmica da bacia hidrográfica do rio Morno, Recife-PE, para evento de inundação considerando regime de chuvas atuais e mudanças climáticas

Abstract

Urban floods are natural phenomena whose frequency and severity have intensified over the past decades, driven by unplanned urbanization, soil impermeabilization, and climate change. In this context, the study of hydrological and hydrodynamic dynamics becomes essential for urban planning and disaster risk management. This study analyzed the flood vulnerability of the Morno River basin, located in the municipality of Recife, Brazil, using computational modeling applied to extreme flood events. Hydrological modeling was carried out using HECHMS, considering two precipitation scenarios: the current one, based on the Recife Drainage Master Plan, and a future one, incorporating the effects of climate change. Subsequently, the hydrographs generated were integrated into a 2D hydrodynamic model using HEC-RAS, with a high-resolution digital terrain model (DTM) to simulate flood wave propagation and delineate flood extents. The results showed that the most urbanized sub-basins presented higher volumes of excess rainfall and peak discharges, while vegetated areas demonstrated a greater capacity for water retention. Additionally, a significant increase in both the flooded area and the average flood depth was observed under the climate change scenario, with a marked growth in zones classified as extreme hydrodynamic risk. The analysis reinforces the need to revise urban drainage strategies and adapt public policies in response to the intensification of extreme events expected in the future.