Patterns and structures of variables used in social vulnerability index studies in Asia: a systematic review and network-based analysis

Natural hazards cause significant damage and intensify social inequalities, with impacts varying by geographic and socioeconomic contexts. The Social Vulnerability Index (SVI) is widely used to assess such disparities by identifying populations and areas particularly vulnerable due to pre-existing social and structural conditions. While most SVI-related studies have focused on the United States and other developed countries, research on Asian regions has increased in recent years, often incorporating context-specific variables. However, the subjective variable selection for index construction may hinder reproducibility and comparability across studies. To address this issue, we conducted a systematic review of SVI research performed in Asian countries to identify commonly used variables and domains, examine specific case applications, and provide a foundation for enhancing the consistency and comparability of SVI in Asia. The review included only peer-reviewed publications in English or Korean that met our research objectives. Systematic searches were carried out across academic databases, including Google Scholar, PubMed, Elsevier, Springer, Scopus, and ProQuest, covering publications up to October 31, 2024. Ultimately, 22 studies were selected, from which 61 variables and 16 domains were initially identified. Further analysis revealed that domains such as gender, age, household structure, education, and infrastructure accessibility, along with their sub-variables, were critical components. These sub-variables were found to interact in shaping social vulnerability. This study contributes to clarifying the basis of variable selection rooted in the Asian social context and offers foundational insights for future SVI development that accounts for both theoretical coherence and regional relevance.