Considerações preliminares do atlas de movimentos gravitacionais de massa do Estado de Santa Catarina – Brasil

Abstract

This technical report is a preliminary description of data analysis about landslides occurrence in the state of Santa Catarina, Southern Brazil. The projects Setorização de Áreas de Risco Geológico and Cartas de Suscetibilidade a Movimentos Gravitacionais de Massa e Inundações developed by the Geological Survey of Brazil and executed between 2011 and 2019 in respectively 295 and 98 cities of Santa Catarina, provided the data for this analysis. Afterwards, an inventory of slope failures was carried outusing Google Earth resources. The interpretation of the data of landslides and geology, geomorphology, soil types and geomorphometric parameters showed the triggering conditions of natural and anthropically induced landslides. The results indicated that slope failure are the main typology and occur in high and very high risk areas. The risk sectors are widely distributed, even though the inventory of slope failures evidences that the most events was concentrated in Serra do Leste Catarinense and Escarpa do Serra Geral regions. The analyses of geomorphometric parameters for slope failure demonstrated that these processes occur majorly in slopes with at least 20% of slope; mainly on the north, northeast and northwest faces, and slopes with convex-divergent and concave-convergent shapes. The Atlas of Hazards of Landslides for Santa Catarina has been developed the Geological Survey of Brazil as described in this report and the preliminary results have demonstrated the main characteristics of favorable areas for the triggering of landslides.