Investigation of natural hazard related to mass movements in the Boi River basin, southern Brazil, with SHALSTAB and Hyper KANAKO.

Abstract

Abstract Extreme rainfall events have been more frequent, resulting in an increase in potentially catastrophic natural phenomena such as landslides and debris flows. To reduce disaster risk related, the hazard mapping for these phenomena is essential. Therefore, the objective of this study was (i) characterize geotechnical units with field survey in a mountain basin, southern Brazil; (ii) apply the combination of the SHALSTAB and Hyper KANAKO models to the basin; (iii) perform a hazard mapping to landslides and debris flows; and (iv) understand better these phenomena. The study area is the Boi River basin at the Caminhos dos Cânions do Sul Geopark, which is a part of the largest canyon chain in South America. The simulated scenarios showed that the occurrence of debris flows in the region represents a real danger for tourists and residents, with locations where these phenomena reach the trails with speeds greater than 50 km.h-1 and depths greater than 5 m.