DADOS GEOLÓGICOS E DE SENSORIAMENTO REMOTO APLICADOS AO MAPEAMENTO DA SUSCETIBILIDADE A MOVIMENTOS DE MASSA: ESTUDO DE CASO EM MAIRIPORÃ, ESTADO DE SÃO PAULO - BRASIL

Abstract

This paper presents the mapping of landslide susceptibility in the municipality of Mairiporã-Brazil, using geological, geomorphological and environmental data processed in a GIS environment. This methodology was developed seeking the generation of maps by using only free spatial data and computer software. Landsat 8 satellite images, Shuttle Radar Topographic Mission radar images and geological data were used as input data for this study, which generated slope, vertical curvature, land use, lithology and lineament density maps. A numerical and weighting system was applied to compose the Susceptibility Map. The resulting landslide susceptibility map delineates the area into different zones of four relative susceptibility classes: high, moderate, low, and very low. The map was validated by correlating the susceptibility classes to the occurrence of mass movement events registered in the municipality and by comparison with preexisting landslide susceptibility maps. This has shown a close agreement with the existing instability conditions. Results showed that approximately half of the municipality's area is located in zones Very Low (4.9%) and Low (44.9%), while the area classified as Moderate corresponds to 34.4% of the municipality area and the High class totaled 15.8%. The areas where susceptibility was classified as High are those with high slopes, metamorphic rocks, and bare soil.