摘要Social vulnerability,as one of the risk com-ponents,partially explains the magnitude of the impacts observed after a disaster.In this study,a spatiotemporally comparable assessment of social vulnerability and its drivers was conducted in Portugal,at the civil parish level,for three census frames.The first challenging step consisted of the selection of meaningful and consistent variables over time.Data were normalized using the Adjusted Mazziotta-Pareto Index(AMPI)to obtain comparable adimensional-normal-ized values.A joint principal component analysis(PCA)was applied,resulting in a robust set of variables,interpretable from the point of view of their self-grouping around vulner-ability drivers.A separate PCA for each census was also conducted,which proved to be useful in analyzing changes in the composition and type of drivers,although only the joint PCA allows the monitoring of spatiotemporal changes in social vulnerability scores and drivers from 1991 to 2011.A general improvement in social vulnerability was observed for Portugal.The two main drivers are the economic condi-tion(PC1),and aging and depopulation(PC2).The remain-ing drivers highlighted are uprooting and internal mobility,and daily commuting.Census data proved their value in the territorial,social,and demographic characterization of the country,to support medium-and long-term disaster risk reduction measures.