Geotechnologies for Mapping and Risk Assessment of Infrastructure Near Coastal Cliffs
Environmental risk, Cliffs, Geoprocessing, Coastal Infrastructure, UAV.
Brazilian coastal zones are characterized by high environmental dynamism and increasing anthropogenic pressure, particularly in tourist areas where urban expansion encroaches upon naturally unstable environments. In this context, coastal cliffs constitute geomorphological systems that are highly susceptible to erosive processes, whose instability represents a significant risk to infrastructure and public safety. This dissertation aimed to analyze the geomorphological risk associated with infrastructures located on the cliffs of Praia do Centro de Pipa, in the municipality of Tibau do Sul (RN), through the integrated application of geotechnologies, remote sensing, and spatial analysis within a Geographic Information Systems (GIS) environment. The methodological approach was grounded in Modern Cartography and structured into four main stages: bibliographic and regulatory review; construction of a geospatial database; systematic field activities; and data processing and analysis in GIS. Orbital remote sensing products and aerophotogrammetry obtained by Remotely Piloted Aircraft Systems (RPAS) were employed, enabling the generation of high-resolution orthomosaics and Digital Surface Models (DSM). Risk assessment was conducted through an adaptation of the risk indication mapping method, integrating geomorphological hazard, spatial exposure, and consequences associated with infrastructure within three distance buffers from the cliff edge: 10, 33, and 100 meters. The results reveal a scenario of high socio-environmental vulnerability, marked by the presence of active basal undercutting processes, subaerial erosion, irregular drainage, and block deposits at the base of the cliffs. Spatial risk classification demonstrated that the most critical sectors are concentrated within 10 meters of the cliff edge, where sensitive infrastructures were identified, including a cemetery. Intermediate distance zones from the cliff edge presented predominantly low to moderate risk up to 33 meters, whereas the outermost buffer, extending up to 100 meters, comprises areas of residual risk.