Mapeamento da suscetibilidade a movimentos gravitacionais de massa do município de Mogi das Cruzes – SP utilizando dados geoespaciais
Data
2021-08-12
Autores
Soffo, Larissa Morelli [UNIFESP]
Orientadores
Soares Junior, Adilson Viana [UNIFESP]
Tipo
Trabalho de conclusão de curso de graduação
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Os movimentos gravitacionais de massa, conhecidos como “deslizamentos de terra” são processos que ocorrem naturalmente no meio ambiente, porém, quando somados às diversas ações antrópicas que causam a modificação do ambiente e à ocupação de locais desfavoráveis em termos geológicos e geomorfológicos, podem resultar em tragédias de grandes proporções. Visando à prevenção e minimização dos impactos e prejuízos gerados por estes desastres, faz-se necessário o planejamento e execução de estudos de mapeamento de suscetibilidade a movimentos de massa, os quais utilizam diversas metodologias para interpretação e análise ambiental de diferentes terrenos e são ferramentas de auxílio ao Poder Público na concepção de medidas para a redução dos danos e perdas e no planejamento urbano. No presente trabalho, realizou-se este mapeamento para o município de Mogi das Cruzes - SP utilizando o programa QGIS e imagens do satélite Landsat 8 e dados do radar SRTM; a Carta de Suscetibilidade foi gerada através da junção algébrica de cinco mapas geotécnicos: uso e ocupação do solo, declividade, litologia, concentração de lineamentos e curvatura de vertentes, sendo que cada um consiste em um fator condicionante ao qual foi atribuído um peso conforme o grau de influência na ocorrência de movimentos de massa. Os resultados indicaram que há uma predominância de áreas com suscetibilidade baixa a moderada no município de estudo, porém também ocorrem áreas com alta suscetibilidade que precisam de atenção; além disso, ocorreu a validação do método como um procedimento acessível e fácil para a elaboração de cartas de suscetibilidade.
Gravitational mass movements, also known as “landslides”, are processes that occur naturally in the environment, however, when issues such as anthropic actions that cause environment modification and human occupation at geological and geomorphological adverse locations are added up to those territories, it can result in great proportions tragedies. Aiming at the prevention and minimization of the impacts and damages generated by these disasters, it is necessary to plan and execute susceptibility mapping studies to mass movements, which use different methodologies for interpretation and environmental analysis of different terrains and consists in tools for assistance to the government in the elaboration of measures to reduce damage and losses and in urban planning. In the present work, this mapping was accomplished for the city of Mogi das Cruzes - SP using the QGIS software and Landsat 8 satellite images and SRTM radar data; the Susceptibility Chart was generated through the algebraic joining of five geotechnical maps: land use and occupation, slope, lithology, concentration of lineaments and slope curvature, each consisting of a conditioning factor to which a weight was assigned according to the degree of influence on the occurrence of mass movements. The results indicated that there is a predominance of areas with low to moderate susceptibility in the studied municipality, but there are also areas with high susceptibility that need attention; furthermore, the method was validated as an accessible and easy procedure for the elaboration of susceptibility charts.
Gravitational mass movements, also known as “landslides”, are processes that occur naturally in the environment, however, when issues such as anthropic actions that cause environment modification and human occupation at geological and geomorphological adverse locations are added up to those territories, it can result in great proportions tragedies. Aiming at the prevention and minimization of the impacts and damages generated by these disasters, it is necessary to plan and execute susceptibility mapping studies to mass movements, which use different methodologies for interpretation and environmental analysis of different terrains and consists in tools for assistance to the government in the elaboration of measures to reduce damage and losses and in urban planning. In the present work, this mapping was accomplished for the city of Mogi das Cruzes - SP using the QGIS software and Landsat 8 satellite images and SRTM radar data; the Susceptibility Chart was generated through the algebraic joining of five geotechnical maps: land use and occupation, slope, lithology, concentration of lineaments and slope curvature, each consisting of a conditioning factor to which a weight was assigned according to the degree of influence on the occurrence of mass movements. The results indicated that there is a predominance of areas with low to moderate susceptibility in the studied municipality, but there are also areas with high susceptibility that need attention; furthermore, the method was validated as an accessible and easy procedure for the elaboration of susceptibility charts.