HR: 1340h
AN: S23A-0225    [Abstracts]
TI: The monetary earthquake risk of building damages of regions and countries - discussion of the modelling, the comparability and different factors of influence
AU: * Raschke, M
EM: MathiasRaschke@t-online.de
AF: Co. M. Raschke, Teichgasse 18, Weimar, 99423 Germany
AB: The risk of earthquake damages is described in the seismology and earthquake engineering almost exclusively by earthquake scenario of a city or a small region. This approach is denoted in this work with "simple earthquake risk analysis". In contrast, there are models and software in the insurance and reinsurance sector which determine the mean frequency of earthquake events in relation to their cumulated monetary damages. Frequently, the basic principles of the models of this "complete earthquake risk analysis" are not accessible and are not discussed in the science community. The complete earthquake risk analysis of cumulated monetary building damages caused by earthquakes are modelled and discussed in this work. For this purpose, the basic modelling of a complete earthquake risk analysis for a larger region is presented and discussed. The risk calculation was performed by applying QuakeRisk - a commercial program for the insurance sector. The basis of risk analysis is always the models of the earthquake hazard. Parts of the risk analysis of regions and the hazard analysis of sites are comparable to a certain extend. Indeed there are differences too: The scattering in the attenuation relation cannot be considered in risk analysis in the same way as in the hazard analysis. There are fundamental differences between the hazard analysis of different sites and the complete risk analysis of a region. The hazard models of different risk models should be comparable because they are an important part of the risk analysis. The mean of the mean frequency of the locale earthquake strength of all sites of a region is introduced for this purpose. The mean of the mean frequency of the locale earthquake strength of different models for a region should not show significant differences if the cumulated mean frequency of the earthquake events of all sources in the region is equal and the attenuation relations are similar. The differences in the models are related to the geographic distribution and concentration of the earthquake sources in this case. This is demonstrated with different model calculations. The discovering of lack of knowledge regarding the attenuation relations is a result of this part of the work presented. The relation between earthquake damage and the local earthquake strength (PGA, intensity), that is called damage function here, is an important part of the risk modelling. The damage is quantified here as monetary damage or loss in relation to the cumulated value of the buildings of a region. The relation between damage and locale earthquake strength is a relation between the mean value of the damage of all buildings or of all building of a certain type of buildings and the locale earthquake strength. The damage of all locale buildings is a statistic distribution and a probability respectively. The Beta distribution describes the damage good as shown in this work. The scattering in the damage distribution is not important if all damages have to be calculated as shown in the article. The scattering is important if insurance parameter like limit and deductible are considered. The influence of the damage function on the earthquake risk is very important. This is shown in a risk analysis for Germany. The influence of the attenuation relation, the maximum earthquake, the insurance parameter and the scattering in the damage distribution is demonstrated with results of the model calculation. Finally it can be concluded that for the risk analysis there is a large demand of investigation with respect to the damage function, the scattering of the damage distribution, the building stock and the attenuation relation.
DE: 7200 SEISMOLOGY
DE: 7212 Earthquake ground motions and engineering seismology
SC: Seismology [S]
MN: Fall Meeting 2005