Probabilistic Landslide Hazard Methodology, an Application to a Susceptible Area to Landslides in Colombia

Abstract

A Probabilistic method was previously used to perform Probabilistic Hazard Zonation in El Salvador using a new proposed probabilistic methodology (Rodriguez, Yepes 2011). The current project is a case study that uses the same methodology and tries to cover the limitations of the previous and first application, and applied to two historically unstable landslides in Pipiral, an unstable area in the Central Region of Colombia. The susceptibility angle was used as the susceptibility function. Rainfall and earthquakes are considered as landslides triggers. Besides zonation, modeling was performed because the probability model was initially designed to do the zonation of larger areas. A database from “four countries in Central-America and Colombia” of Rainfall Induced Landslides in Fine-grained soils and a database of “historic and worldwide” Earthquake Induced Landslides, were considered to support the model. The intensity-duration-frequency (I-D-F) curves for the Pipiral-Colombia were used to define the probability of occurrence of the critical rainfall, and the seismic hazard analysis of the same area was used to define the probability of occurrence of the critical earthquake.