Carta de suscetibilidade a movimentos gravitacionais de massa no município de São José dos Campos – SP
Data
2023-01-04
Autores
Almeida, Juliana Viegas de 
Orientadores
Soares Junior, Adilson Viana
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A intensificação do processo de urbanização e da ocupação desordenada em zonas de instabilidade geológica e geomorfológica criam áreas de risco a perdas sociais e econômicas por desastres naturais provocados por movimentos gravitacionais de massa. Torna-se evidente a necessidade de mapeamento de áreas suscetíveis a movimentos de massa, como ferramenta de gestão do ordenamento territorial e planejamento urbano. Este trabalho tem como objetivo a elaboração de carta de suscetibilidade a movimentos gravitacionais de massa no Município de São José dos Campos (SP) por meio de técnicas de geoprocessamento de dados gratuitos de geologia e sensoriamento remoto. Empregou-se a metodologia de combinação qualitativa de mapas temáticos e classificação dos fatores condicionantes (Declividade, Litologia, Uso do solo, Curvatura Vertical e Densidade de Lineamentos), seguida de cruzamento de dados e validação da carta final. Os resultados indicaram que as áreas classificadas como pouco estáveis e instáveis foram preponderantes (31,74% e 24,06% respectivamente, cuja soma equivale a 55,8% da área total), caracterizadas por relevos abruptos, onde predominam vertentes com perfis convexos e côncavos, gnaisses e migmatitos, densidade de lineamentos moderada a muito alta e baixa ocupação humana. As áreas estáveis (44,19%) foram associadas ao substrato sedimentar, predominante em zonas de planície aluvial, com baixa e muito baixa densidade de lineamentos e onde se concentram as áreas urbanas consolidadas. Em termos habitacionais, quase a totalidade das áreas instáveis foram mapeadas em áreas rurais, onde há uma tendência para expansão da ocupação urbana. As áreas instáveis abrangeram 95,8% dos dados de cicatrizes. Concluiu-se que a metodologia proposta é eficaz no mapeamento da suscetibilidade a movimentos de massa, com resultados quantitativos muito semelhantes aos obtidos com a aplicação de procedimentos que envolvem validações em campo.
The intensification of the urbanization process and the disorderly occupation in zones of geological and geomorphological instability create areas of risk to social and economic losses due to natural disasters caused by gravitational mass movements. The need to map areas susceptible to mass movements becomes evident, as a management tool for territorial planning and urban planning. This work aims the elaboration of gravitational mass movements susceptibility map in the city of São José dos Campos (SP) through geoprocessing techniques for free geology data and remote sensing. The methodology of qualitative combination of thematic maps and classification of conditioning factors (Slope, Lithology, Land Use, Vertical Curvature and Lineament Density) was used, followed by data crossing and validation of the final map. The results indicated that the areas classified as less stable and unstable were predominant (31.74% and 24.06% respectively, whose sum is equivalent to 55.8% of the total area), characterized by abrupt reliefs, where predominate slopes with convex and concave profiles, gneisses and migmatites, moderate to very high lineament density and low human occupation. Stable areas (44.19%) were associated with the sedimentary substrate, predominant in floodplain areas, with low and very low density of lineaments and where consolidated urban areas are concentrated. In terms of habitation, almost all the unstable areas were mapped in rural areas, where there is a tendency for urban occupation to expand. Unstable areas covered 95.8% of the scar data. It was concluded that the proposed methodology is effective in the mass movements susceptibility mapping, with quantitative results very similar to those obtained with the application of procedures involving field validations.
The intensification of the urbanization process and the disorderly occupation in zones of geological and geomorphological instability create areas of risk to social and economic losses due to natural disasters caused by gravitational mass movements. The need to map areas susceptible to mass movements becomes evident, as a management tool for territorial planning and urban planning. This work aims the elaboration of gravitational mass movements susceptibility map in the city of São José dos Campos (SP) through geoprocessing techniques for free geology data and remote sensing. The methodology of qualitative combination of thematic maps and classification of conditioning factors (Slope, Lithology, Land Use, Vertical Curvature and Lineament Density) was used, followed by data crossing and validation of the final map. The results indicated that the areas classified as less stable and unstable were predominant (31.74% and 24.06% respectively, whose sum is equivalent to 55.8% of the total area), characterized by abrupt reliefs, where predominate slopes with convex and concave profiles, gneisses and migmatites, moderate to very high lineament density and low human occupation. Stable areas (44.19%) were associated with the sedimentary substrate, predominant in floodplain areas, with low and very low density of lineaments and where consolidated urban areas are concentrated. In terms of habitation, almost all the unstable areas were mapped in rural areas, where there is a tendency for urban occupation to expand. Unstable areas covered 95.8% of the scar data. It was concluded that the proposed methodology is effective in the mass movements susceptibility mapping, with quantitative results very similar to those obtained with the application of procedures involving field validations.