Micromorfologia aplicada à evolução e comportamento dos solos na Serra do Mar (Itaipava - RJ).

Abstract

The increase in occupation and land use in places affected by the 2011 disaster in areas with a history of mass movements could increase the chances of fatalities and damage caused by new extreme events, especially in times of climate change. The Cuiabá Valley, in Itaipava, in the mountain region, has experienced an increase in occupation since the 2010's, even though it was one of the main areas affected by the mega disaster. Therefore, the Cuiabá River Basin Valley, where shallow landslides and mass flows were concentrated in the drainage system, was chosen as the study site. Understanding the behavior of soils and their evolution as agents of processes such as mass movements provides an answer as to whether the region's soils are intrinsically susceptible to landslides. Using micromorphology, it was possible to identify features and constituents in the soils under study that could lead to the outbreak of disruptive processes. By cross-referencing the mapping of landslide marks from the 2011 events with the micromorphological analysis carried out, it was possible to identify characteristics of the soil in order to understand its behavior. Micropedology identified that, of six analysis points, one found the pedological feature of gibbsite boxwork, which interferes in the hydraulic conductivity of the soil profile, saturating it upstream and ultimately leading to the rupture of its resistance.