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| Author(s): |
Marina Tamaki de Oliveira Sugiyama
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Filosofia, Letras e Ciências Humanas (FFLCH/SBD) |
| Defense date: | 2025-06-06 |
| Examining board members: |
Bianca Carvalho Vieira;
Victor Carvalho Cabral;
Susana da Silva Pereira
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| Advisor: | Bianca Carvalho Vieira; Maria Carolina Villaça Gomes |
| Abstract | |
Geoparks are regarded as one of the most effective initiatives for the conservation of geoheritage, as they encompass within a defined area, geosites of international, national, or local relevance. However, one of the challenges related to the management of these territories is the potential impact on society and inhabitants resulting from active geomorphological processes. The UNESCO Caminho dos Cânions do Sul Geopark (GCCS), located in southern Brazil, features a landscape deeply marked by mass movement processes. The recognition of the GCCS as a member of the UNESCO Global Geoparks Network in 2022 reinforced the need for the development of reduction and preventive plans for risk and disaster. Thus, this research aimed to analyze the susceptibility and physical vulnerability to landslides within the GCCS. Three mass movement inventories were developed using a semi-automatic method (Object-Based Image Analysis). The susceptibility of the territory was mapped using the Information Value method and analyzed across four different modeling domains based on geomorphological compartmentalization and all possible combinations of predisposing factors, resulting in 480 scenarios. Based on the analysis of model performance and the conditional independence between predisposing factors, three models were selected to compose the final susceptibility map, which resulted in 59.5% of the area classified as very low susceptibility, 19.7% as low, 12.1% as moderate, 5.4% as high, and 3.3% as very high. Ten geosites are located in areas of moderate to very high susceptibility. The vulnerability analysis was carried out using the Papathoma Tsunami Vulnerability Assessment (PTVA) method, adapted for the analysis of physical vulnerability to landslides in an experimental area, where 131 buildings were mapped and their construction characteristics analyzed. The results indicate 31 buildings with moderate vulnerability, 23 with high vulnerability, and 77 buildings with very high vulnerability. Furthermore, by analyzing the buildings in two time-frames (2013 and 2024), a 46.6% increase in the number of constructions was identified; however, the construction patterns remained the same, with a continued predominance of very high vulnerability structures. The final susceptibility map produced satisfactory results, allowing the identification of geosites located in areas susceptible to landslides or within potential transport and deposition zones. The vulnerability assessment, based on the number of existing buildings in two different time periods, reaffirmed the need to evaluate the hazard related to mass movements and other hydrodynamic processes. Thus, the results of this research could significantly contribute to the development and implementation of prevention, mitigation, and risk management plans within the GCCS territory. These plans can support the protection of geoheritage and the safety of tourists and are especially urgent given the expected changes in the frequency and magnitude of mass movements due to alterations in rainfall patterns resulting from climate change (AU) | |
| FAPESP's process: | 22/09132-6 - Assessing landslides susceptibility and vulnerability in the Caminhos dos Cânions do Sul Geopark (RS/SC): Tools to support preventive risk and disaster reduction plans |
| Grantee: | Marina Tamaki de Oliveira Sugiyama |
| Support Opportunities: | Scholarships in Brazil - Master |