Landslides and Disasters in Southeastern and Southern Brazil

Abstract

Abstract Landslide conditions and problems involve functional relationships among natural elements (climate, topography, rocks, soil, vegetation and fauna) and artificial elements (related to land use) of the landscape, which may change over space and time. Two characteristic rainfall regimes might express rainfall–landslide relationships in southern and southeastern Brazil: less intense events of longer duration tend to favor deep rotational failures along channel banks and road cuts, colluvium-deposit creep in valley bottoms, and shallow translation failures on steep lands; extreme rainfall events tend to favor shallow translational slides and debris flows on steep lands, block-rich debris avalanches along main valley bottons and rock falls on vertical scarps. Landslide disasters are commonly associated with less frequent, intense, and spatially nonuniform rainfall events during the summer rainy periods. Critical events have prevailed along the highly populated coastal region, especially in the upper portion of steep mountain slopes. In this text the authors draw special attention to case studies of historical landslide disasters in the most populated area of Rio de Janeiro State, and also include some other case studies in southeastern and southern Brazil.