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.

Assessment of seismic damage to buildings in resilient Byblos City

“…Another interesting method was developed and presented in [65]. It proposes three city models for loss estimates: the simplest describe the city model by one coordinate point; the most sophisticated model would have the position, type, occupancy of every building known; and the intermediate model is used when the information concerning the parameters needed for loss estimates is limited.…”

Report estimated quake death tolls to save lives

“…Yet QLARM includes detailed soil and building data for only around 70 large cities (with populations in the millions). City districts need mapping to understand their seismic responses 7 . Making an informative model for a large city costs about $100,000.…”

Vulnerability to Earthquake Hazard: Bucharest Case Study, Romania

“…6), which shows dense, concentrated areas of very high vulnerability in most of the peripheral zones of the city where more small residences tend to be found rather than large blocks of flats. The areas identified as being vulnerable reveal an image validated by past events and the results of previous studies (Rufat 2009;Trendafiloski et al 2009;Armaş 2012;Armaş and Radulian 2014;Toma-Danila et al 2015a). …”