- site under construction -
Calculation of losses at national and subnational level
An open and transparent seismic risk assessment for the Andean countries has been performed. A probabilistic approach was followed for the calculation of risk metrics, that includes average annual economic and human loss maps, mean loss exceedance curves per country, and statistics that reveal which building classes are most vulnerable to earthquakes.
The OpenQuake-engine was used in the estimation of losses, utilizing the hazard model, exposure and physical vulnerability models presented in the corresponding sections. An event-based Monte Carlo simulation with 50.000 synthetic catalogues, or stochastic event sets (SES), representative of the seismicity of the region over a period of one year were generated for each country. For each rupture, a ground motion field is generated taking into account the inter- and intra-event variability suggested in the GMPE. In addition, the uncertainties coming from the selection of GMPEs are included through the use of logic trees for the different tectonic region types.
The present section presents a summary of the different risk metrics at regional scale. For additional data for a specific country, users can follow the corresponding links:
Average Annual Losses (AAL)
It is one of the most common loss statistics generated in risk assessment. This statistic allows a direct comparison of the expected losses in different areas. Regarding the spatial distribution of losses in South America, the figure below presents the distribution of mean AAL at the first administrative level in the seven studied countries.
These types of results allow the identification of the regions with the highest potential economic losses within a country, and thus where risk reduction activities should be prioritized. The AAL can also be aggregated at different geographical levels. For example, Fig. 5 (bottom-right) presents the mean average annual loss ratio (AALR, ratio between the total mean AAL with the total exposed value) for each country. The results indicate that Ecuador and Chile are the countries with larger AALR, 0.44% and 0.21%, while Argentina is the country with the lowest value, 0.02%.