Aerophotogrammetry with UAV applied to the registration of buildings in landslides risk areas on urban slopes in the northern zone of Recife, Pernambuco, Brazil

Abstract

This study investigates the application of Unmanned Aerial Vehicles (UAVs) for the registration and risk assessment of buildings in urban slopes prone to landslides in the Dois Unidos neighborhood, North Zone of Recife, Pernambuco, Brazil. The region faces significant challenges due to irregular occupation and territorial fragmentation, increasing its vulnerability to disasters. Using UAV-based photogrammetry, the research conducted a cadastral survey in the area, identifying 513 buildings. Furthermore, these data were integrated with a landslide susceptibility analysis based on statistical methods, considering factors such as slope, curvature, aspect, Specific Pluviometric Index (SPI), Topographic Wetness Index (TWI), and Height Above the Nearest Drainage (HAND) using the Digital Terrain Model (DTM) from the Pernambuco Tridimensional Project (PE3D, 2016). The integration of these data allowed for a more precise analysis of the involved risk, essential for the implementation of effective preventive and mitigating measures against landslides, thereby enhancing risk and disaster management in vulnerable urban areas. In addition to UAVs and photogrammetry, the study highlights the importance of field inspections to verify specific conditions of buildings, such as infrastructure, rudimentary sewage systems, and proximity to high-risk areas. This combined approach of remote sensing technology and on-site validation provides a low-cost, high-precision solution for updating building registries in vulnerable urban areas, facilitating more effective management of environmental and urban risks.