Comparing a simulated loss scenario with the observed damage: the Lorca 2011 case study

Abstract

A loss assessment was performed for the buildings of Lorca, Spain, considering an earthquake hazard scenario with similar characteristics to those of a real event which occurred on May 11th 2011, in terms of epicentre, depth and magnitude. This low-to moderate earthquake caused severe damage and disruption in the region and especially on the city. A building by building resolution database was developed and used for damage and loss assessment. The portfolio of buildings was characterized by means of relevant indexes capturing information from a structural point of view such as age, main construction materials, number of stories, and building class. A replacement cost approach was selected for the analysis in order to calculate the direct losses incurred by the event. Hazard and vulnerability were modeled in a probabilistic way, considering their inherent uncertainties which were also taken into account in the damage and loss calculation process. Losses have been expressed in terms of the mean damage ratio of each dwelling and since the analysis has been performed on a geographical information system platform, the distribution of the damage and its categories was mapped for the entire urban centre. The simulated damage was compared with the observed damage reported by the local authorities that inspected the city after the event.