Application of the Hazard Mapping Methodology From the Geological Survey of Brazil for Geotourism Attractions

In January 2022, ten people died when a boulder fell on a tourist boat on Lake Furnas, in the municipality of Capitólio-MG. As a result, since the tragedy, the Geological Survey of Brazil has been conducting geological-geotechnical assessments in areas where ecotourism activities are carried out, with the aim of helping to improve environmental management practices and safety conditions for tourists and other professionals who visit these regions. One of these areas is the José Lutzenberger State Park, located in the municipality of Torres, in the state of Rio Grande do Sul, Brazil. Geologically speaking, it is a group ofiselbergs formed by basalt outcrops in the middle of an extensive coastal plain, creating a relief of cliffs that is much sought after by tourists and fishermen. Geologic hazard mapping was performed by collecting structural, lithological and geomorphologic data and geodynamic features of terrain instability in the face of gravitational mass movements. An unmanned aerial vehicle (drone) was also used to generate a digital elevation model as input for modeling. The analyses presented in this paper were carried out using the hazard methodology of the Brazilian Geological Survey, adapted from the manual developed by the GIDES-JICA project, which consists of dividing the analyzed slope into critical and dispersion areas and then assigning a degree of risk according to the variety and intensity of the observed evidence. The work allowed the identification of the safe areas in the park and the delimitation of areas subject to geological accidents, classified according to the degree of hazard of translational landslides and rockfalls.

Keywords: Geotechnical assessment of geotourism attractions, Geohazard mapping methodology, José lutzenberger state park.