HEC-HMS, HEC-RAS, Tapacurá River Basin.

Uncontrolled and unplanned urbanization, combined with projections of climate change, point to a scenario of increased vulnerability of people and infrastructure to urban flooding. In this context, the city of Vitória de Santo Antão, in the Zona da Mata region of the state of Pernambuco, stands out. It has grown around the Tapacurá River, occupying its floodplain. This city has already suffered from catastrophic flood events in the past, with notable events occurring in 2005, 2010, and 2011, affecting an estimated 3.26 million people, resulting in 162 deaths, and causing costs in the order of R$13.52 million. The aim of this study was to conduct 2D hydrological and hydrodynamic modeling using Remote Sensing techniques and a high-resolution digital terrain model to geospatially analyze the occurrence of floods and obtain maps with indicators and danger indexes for the urban center of Vitória de Santo Antão. The digital terrain model was obtained through laser profiling and made available by the Pernambuco Tridimensional project. The hydrological and hydrodynamic models were implemented using the freely accessible software HEC-HMS and HEC-RAS, respectively. The calibration and validation of the hydrological model were performed using available flow data, and a real event that occurred in May 2011 was simulated. The calibration achieved a Nash-Sutcliffe efficiency coefficient of 0.940. The simulations successfully reproduced the flood extent throughout the municipality, covering an area of 2,993 km² and reaching water depths of up to 5.65 m. With the simulation results, it was possible to create maps with hazard indicators and indices. It is expected that the information produced here can contribute to the decision-making process of the managing authorities, enabling the adoption of structural and/or non-structural measures to prevent or mitigate the monetary and life losses associated with flooding.