Abstract
Based on the disaster risk framework proposed by the United Nations Office for Disaster Risk Reduction and the Intergovernmental Panel on Climate Change, this study defines seismic risk as a function of seismic hazard, population-building exposure and vulnerability. The Chi-Chi, Taiwan, earthquake was used as a case study of a two-step cause and effect (housing damage and fatalities) analysis. Data (mostly at village scale) from various governmental and academic sources, including data for demographics, housing tax, family income tax, seismology, housing damage, and fatality, were used to construct four statistical models to examine the physical and social determinants underlying the seismic risk. The Poisson regression model was used to estimate the impacts of these factors on housing collapses and fatalities. The regression models showed that all factors significantly affected housing collapseand fatality. Seismic hazard and population-building exposure are the most key factors. Earthquake intensity, passage of the Chelungpu Fault, collapse of condominium and their intersectional effects explained most earthquake fatalities. Compared with those factors, social vulnerability variables (gender-female, young population, low family income, and income inequality) have a weaker influence; however these variables have a significant marginal effect on enlarging the fatalities. The contribution of this study is the use of an interdisciplinary approach that integrates theories and data across seismology, geology, geography and sociology to enrich seismic risk study. Regarding social implications, this study demonstrates the important role of national institutions, such as urban planning, regional planning, building regulation, and social welfare mechanisms, in minimizing exposure and social vulnerability to seismic risk.