Measuring social vulnerability to natural hazards in China: a modified index approach

Climate-related disasters have adversely affected the livelihoods and well-being of people in both developed and developing countries, including China. Identifying and addressing social vulnerability is an integral element of disaster risk reduction efforts. Various quantitative approaches have been proposed to measure social vulnerability in China, guiding the scale of research and the selection of indicators. Utilizing indicators adapted from the US CDC SVI framework, this study constructs a modified social vulnerability index to evaluate the spatial heterogeneity and regional distribution of social vulnerability in China for the years of 2000 and 2010. The index was developed by the application of Principal Component Aanalysis (PCA) on fourteen socio-economic variables, identifying urbanization, population structure and economic status as major components. The results indicate that the spatial distribution of social vulnerability exhibited a more distinct difference between eastern and western regions than between the northern and southern regions, with social vulnerability increasing from eastern to western China. Exploratory Spatial Data Analysis (ESDA) uncovers significant effect of spatial dependence, with high social vulnerability remained consistently clustered among Chinese counties. Furthermore, to evaluate the robustness and reliability of the constructed index, sensitivity analysis was conducted by constructing the social vulnerability index at various scales and employing different algorithmic approaches with varying weights. This analysis is essential for enhancing the adaptability of a multi-faceted social vulnerability index to various contexts and uses.