Constructing City Models to Estimate Losses Due to Earthquakes Worldwide: Application to Bucharest, Romania

Abstract

We propose a method to calculate damage and human losses for cities in the developing world by averaging over an entire city, or its administrative districts. Bucharest, Romania, serves as an example. First, we modeled this city as located at a single coordinate point. We transformed the census information on building types, ages and height into EMS-98 vulnerability classes and distribute the population into them. We assumed a seismic load of MSK [Formula: see text] (M7.4 1977 Vrancea earthquake). Validating our model by comparison with casualties reported in 1977, we find differences of 20% to 30%. We reduced these errors to about 4%, by adjusting the distribution of building types into vulnerability classes, based on their performance in the 1977 earthquake. Calibrations of this type will be necessary for most developing countries. In a second step, we modeled Bucharest with six districts, in which the distribution of people into building types and the average soil conditions are known. This is our preferred model. We also calculated the soil properties that would be estimated from topography, if microzonation would not be available. The agreement was satisfactory. We propose this method to model important cities in earthquake prone areas of the developing world.