Estimacion del riesgo en edificaciones por deslizamientos causados por lluvias y sismos en la ciudad de Medellin, empleando herramientas de la Geomatica

This article presents a risk estimation in buildings by landslides triggered by earthquakes and rainfall in the city of Medellin using a Geographic Information System (GIS). For this, a computer model that considers topographic, geological, geotechnical and hydrological characteristics of the study area was implemented to determine landslide hazard by evaluating the stability of slopes using pseudo static Newmark Method, including a probabilistic approach technique based on the first order and second moment--FOSM. The approach for the assessment of physical vulnerability of buildings in the study area was conducted through structural fragility indexes that consider the definition of the level of damage to buildings through event trees using a cadastral inventory data of the municipality of Medellin. The routine calculates the probability of a landslide to occur given that an earthquake produces a horizontal ground acceleration (Ah), considering the uncertainty of the geotechnical parameters and the conditions of soil saturation for the effect of previous rainfall in the area, then multiply such values with the structural fragility indexes values in order to estimate the damage indices of buildings, which are associated with the risk when considering the relevant economic variable to the replacement value of such structures from assessed values.