Social Vulnerability Index (SoVI®)
Social vulnerability is the susceptibility of a population to harm from a natural hazard and examines those characteristics of the population that influence their resilience. Vulnerable populations may be less resilient to hazards and disasters than other parts of the population, may need special assistance in preparing for, responding to, and recovering from disasters, and may be more susceptible to economic or other impacts from an event. Social vulnerability is place-based and context-specific, and helps explain why some portions of the country or community experience a hazard differently, despite having the same exposure. Income is but one variable that is often associated with vulnerable populations, and income levels clearly vary by race and ethnicity (Figure 4.1). Other vulnerable populations may include special-needs populations such as residents with physical or mental impairments, the elderly, the young, and those with limited access to transportation (see also Chapter 5).
FIGURE 4.1 Trends in median household income in the United States. Data show income level variations by race and ethnicity. Source: U.S. Census Bureau.
Social vulnerability helps us to understand the inequalities in disaster impacts and is a multiattribute concept that includes socioeconomic status, race and ethnicity, gender, age, housing tenure, and so forth and how these factors influence a community’s resilience (Mileti, 1999; Heinz Center, 2002; NRC, 2006). Social vulnerability can change over time and across space (Cutter and Finch, 2008) and can be measured both qualitatively and quantitatively (Birkmann, 2006; Phillips et al., 2010).