Articles | Volume 18, issue 1
Research article
03 Jan 2018
Research article |  | 03 Jan 2018

Understanding shallow landslides in Campos do Jordão municipality – Brazil: disentangling the anthropic effects from natural causes in the disaster of 2000

Rodolfo M. Mendes, Márcio Roberto M. de Andrade, Javier Tomasella, Márcio Augusto E. de Moraes, and Graziela B. Scofield

Abstract. Located in a mountainous area of south-eastern Brazil, the municipality of Campos do Jordão has been hit by several landslides in recent history. Among those events, the landslides of early 2000 were significant in terms of the number of deaths (10), the population affected and the destruction of infrastructure that was caused. The purpose of this study is to assess the relative contribution of natural and human factors to triggering the landslides of the 2000 event. To achieve this goal, a detailed geotechnical survey was conducted in three representative slopes of the area to obtain geotechnical parameters needed for slope stability analysis. Then, a set of numerical experiments with GEO-SLOPE software was designed, including separate natural and anthropic factors. Results showed that natural factors, that is, high-intensity rainfall and geotechnical conditions, were not severe enough to trigger landslides in the study area and that human disturbance was entirely responsible for the landslide events of 2000. Since the anthropic effects used in the simulations are typical of hazardous urban areas in Brazil, we concluded that the implementation of public policies that constrain the occupation of landslide susceptible areas are urgently needed.

Short summary
The results showed in this paper confirmed that the occurrence of landslides in the study area cannot be attributed solely and exclusively to the rainfall events of the year 2000. Therefore, numerical modelling results corroborated the fact that the occurrence of landslides was the combination of natural and anthropic factors, with the decisive influence of the latter due to the presence of several cuts along the slope combined with load of constructions and leakage.
Final-revised paper