The Disadvantage to the Rural Population in Earthquake Disasters

Wednesday, 17 December 2014
Max Wyss, International Center for Earth Simulation, Geneva, Switzerland
Scenario calculations show that the rural population is more vulnerable to earthquake disasters because of their comparatively weak building stock. For calculating damage due to strong ground shaking, the building stock is modeled separately for different countries and in each country separately in three settlement size classes. It is generally understood that cities contain more buildings that are resistant to strong shaking than villages. A corollary of this observation is that villagers are more likely to be killed by their collapsing homes than city dwellers. The quantitative excess of the vulnerability of villagers compared to city dwellers varies as a function of the following parameters: (1) Country, (2) epicentral distance, and (3) earthquake magnitude, in addition to the quality of the built environment. For estimating quantitatively the difference of mortality in villages compared to cities, we used the building stock as modeled in the earthquake loss estimating tool QLARM. For the scenario calculations, the epicenters and depths of recent large or damaging earthquakes were selected and their magnitudes were set to M7.5, in cases where the magnitude of the historic event had been smaller. The countries for which we estimated the excess rural mortality included: Algeria, China, Greece, Guatemala, India, Iran, Mexico and Turkey. In all of these countries and for all distances the mortality rate was found to be larger in the villages. Depending on the parameters (1), (2) and (3), the percentage of fatalities in villages was higher by 20% to 97% than in cities. In the case of Greece, where the QLARM data are the most detailed, a clear function of the per cent of fatalities as a function of settlement size emerged. Because indigenous peoples live typically in small settlements, these findings mean that the indigenous population is exposed to a greater earthquake risk than the average population. Although it is understandable that earthquake risk mitigation has focused on megacities, the conclusion of this study is that the rural population needs more help in earthquake risk mitigation than the urban population.