GIS-BASED TEST OF A BUILDING VULNERABILITY MODEL: A CASE STUDY OF THE L’AQUILA EARTHQUAKE.
During the year 2002 “Dipartimento Nazionale per la Protezione Civile” (Italian national agency for civil protection) asked for a forecasting model to estimate the building vulnerability in the area of L’Aquila. The model was studied by Professor Beolchini of L’Aquila University; maps representing possible damage to buildings and roads were prepared for the centre of the city. These maps classify the possible damage in four different categories and have a maximum resolution of 25 meters. After the earthquake, which took place in April 2009, it is possible to assess the accuracy of the model comparing predicted damage with actual damage. After the seismic event “Vigili del Fuoco” (Fire Department) engineers inspected every building and tentatively assessed their damage classifying them in six categories. These results were archived in an Access database and also mapped on a 1:2000 city map. To assure the consistency of these data, Access databases were geocoded and cross checked with the damage reported in the map files. When a mismatch between map and database values was observed, damage was studied further with a high resolution satellite image acquired by "Eros-B" satellite several days after the earthquake. The maps so obtained and verified were compared with the maps of the predicted damage, rasterizing the damage reported on the two maps at the same resolution. Thus it has obtained a raster file containing differences between the predicted and observed damage, evidencing that the biggest differences are limited to some small areas. Observing the localization of these areas it seems that there may be a correlation between the largest differences and some geophysical characteristics of the terrain can cause local attenuation or amplification of the seismic waves.
Valerio Baiocchi - Università La Sapienza di Roma
Donatella Dominici - Università La Sapienza di Roma
Rachele Ferlito - Università La Sapienza di Roma
Francesca Giannone - Università La Sapienza di Roma
Massimo Guarascio - Università La Sapienza di Roma
Maria Zucconi - Università La Sapienza di Roma