The Social Vulnerability Index (SVI) from the Centers for Disease Control and Prevention (CDC) and Agency for Toxic Substances and Disease Registry (ATSDR) identifies and quantifies communities experiencing social vulnerability to disasters and public health emergencies. Using 16 U.S. Census variables from the 5-year American Community Survey, the SVI analyzes demographic and socioeconomic factors—including poverty, lack of transportation access, and crowded housing—that adversely affect communities when they encounter hazards like natural disasters, chemical spills, or disease outbreaks.
The SVI organizes vulnerability factors into four key themes: socioeconomic status, household composition and disability, minority status and language, and housing and transportation. Communities receive overall SVI scores ranging from 0 (least vulnerable) to 1 (most vulnerable), with percentile-based rankings at the census tract level.
Emergency planners use the SVI to determine staffing needs, plan evacuation routes, and account for socially vulnerable populations, while public health officials identify areas requiring emergency shelters and estimate supply quantities. State and local health departments, nonprofits, emergency management agencies, and community organizations employ SVI data to guide preparedness initiatives, recovery planning, resource allocation, and health promotion programs, making it essential for reducing human suffering, economic loss, and health inequities during disasters and public health crises.