Multicriteria analysis applied to landslide susceptibility mapping

Abstract

Current human settlements are characterized by disorganized urbanization and high population densities, which can impact the landscape and the environment. Soil transport leads to erosion and aggradation of water bodies and increases landslide susceptibility in regions with more uneven topographies. Landslides are the most common environmental accidents and have caused the most deaths; one example is the incident that occurred in the mountainous region of the state of Rio de Janeiro (Brazil) in January 2011. Mapping the predisposition or susceptibility of components of the physical environment to landslides provides an integrated view of the characteristics and physical processes that act within a region. Therefore, the objective of this study is to evaluate the urban expansion proposal of Baptista (Avaliação da suscetibilidade aos movimentos de massa, erosão e escoamento superficial em Nova Friburgo, RJ, 2009) and compare it with the areas affected by the mega-disaster of 2011 using hierarchical decision analysis and a GIS toolkit. The results show that landslides did not affect the areas selected for urban expansion, i.e., the method was useful for identifying the areas that were most susceptible to landslides prior to the disaster.