Morphological and Geological Susceptibility to Landslides in the Paraitinga-Paraibuna Plateau (SP)

Abstract

The Paraitinga - Paraibuna Plateau is composed by high and elongated hills, with convex tops and steep slopes. This relief is conditioned by the geological structures, such as folds and strike-slip faults; the lithology is composed by medium grade metamorphic rocks and intrusive sintectonic igneous rocks. These morphological and lithostructural features can behave as conditioning factors of landslides- recurring processes on the Paraitinga – Paraibuna Plateau. Thus, the aim of this work was to evaluate the susceptibility to landslides considering geological and morphological aspects of the relief. To evaluate the susceptibility to landslides, the Landslide Potential Index (LP) method was applied. This index is defined by the ratio of the number of scars of each class by the area of each class, the results expressed in percentage (%).The partial results showed that the lithological class of the nebulitc metatexite was the most prone to failure, with a landslide potential value of 222%; and the slope angle class of 30 ° -58 ° was the less stable, with a landslide potential value of 250%. It was also observed that the landslides were concentrated along fold axes and strike-slip faults, indicating a possible structural control.