(January 2011) Increasing disaster threats not only reflect the onset of events such as earthquakes or floods, but also the changing demographic and socioeconomic characteristics of the population. A large, violent tornado, for instance, passing through an open field presents little danger. On the other hand, a relatively weak tornado can pose significant risks to human life and can result in great economic losses in densely populated areas. While the intensity is important, of equal or greater importance is the presence of a population whose demographic or socioeconomic characteristics may place its members at greater risk of harm before, during, and after a disaster.

The "vulnerability" perspective in disasters, which is rapidly emerging as a dominant view in the field, assumes that a real disaster occurs when it strikes an underprivileged population. Vulnerability is formally defined as "the characteristics of a person or group and their situation that influences their capacity to anticipate, cope with, resist, and recover from the impact of a natural hazard."1 Implicit here is "differential vulnerability"; that is, different populations face different levels of risk and vulnerability. Consequently, policies aimed at addressing risk and vulnerability must also take into account these differential impacts and outcomes of disasters. Although the sources of vulnerability are multiple and quite diverse, some of the most important factors that affect vulnerability include population growth and distribution and social diversity.

Population Growth and Distribution

Population growth and distribution, especially increased population density and urbanization, increases vulnerability to disasters.2 Nearly 80 percent of the U.S. population resides in urban areas, resulting in  increasing population concentration in coastal communities and flood-prone areas. Congestion, limited escape routes, dense infrastructure, and poverty add to the vulnerability. Cities and countries in other regions of the world face similar problems. For example, researchers argue that in countries such as China, urban earthquakes are more dangerous because of the density of the infrastructure.3 The growth of coastal populations, for instance, raises important concerns about increased human exposure to coastal flooding, hurricanes, and tsunamis.4 The organization of work and leisure around coastal areas in India was one of the factors that resulted in high rates of injuries and fatalities following the 2004 Indian Ocean tsunami.5

Social Diversity

While population growth and distribution are important factors in producing vulnerability, who is being affected by the disaster is equally important. The social and economic characteristics of a group may limit its members' abilities to protect themselves from harm, but the culture of social groups also plays an important role. For example, one key factor regarding why Latinos may suffer higher vulnerability to disasters in the United States may relate to their language abilities. Commonly issued in English, disaster warnings may be misunderstood or not understood at all by Spanish-speaking individuals.6 Other culturally driven perceptions among migrant workers may also contribute to exacerbating vulnerability and inhibiting the appropriate response, especially when going to an evacuation shelter may result in deportation.7 Moreover, the Latino population in the United States has lower levels of income and higher levels of poverty than the population at large, making it more difficult for Latinos to prepare for, respond to, and recover from disasters.8

Although culture is important, poverty is a primary factor that affects how individuals perceive risk and how well they understand and respond to warnings.9 Widespread poverty has played a critical role in increasing population vulnerability to many recent disasters, including Hurricane Katrina, the Indian Ocean tsunami, and the 2009 Haitian earthquake.10 Hurricane Katrina is a primary example of how the adverse effects of disasters disproportionately affect the poor and people of color.11

Women also confront unique challenges when facing disasters. Despite literature that suggests women are more likely to recognize and respond to risk, women tend to be poorer relative to men and may not have the necessary resources to respond to and recover from disasters. This problem is particularly evident among single mothers, whose poverty rates exceed that of single or married women, and who must not only protect themselves but must also safeguard the lives of their children when threats emerge. During the 2004 Indian Ocean tsunami, women and children were more likely to suffer injuries and fatalities than men and boys were. Women's vulnerability to disasters is also shaped by traditional gender roles, power and privilege, low wages, and secondary responsibilities such as child care.12

Other factors that affect vulnerability include age and disability. The effects of age and disability on disaster vulnerability were clearly seen among elderly individuals trapped in nursing facilities during Hurricane Katrina. Moreover, it is estimated that individuals ages 65 and older represented over 70 percent of the fatalities from Hurricane Katrina.13

How will national and global population distribution and the increasing presence of disadvantaged groups continue to affect public safety? How can we expand and strengthen our research initiatives to enhance our understanding of differential vulnerability and to develop more effective policies to protect diverse population groups from disasters, while recognizing the unique risks and vulnerabilities that underrepresented groups confront? How can we continue to move governments and decisionmakers to develop and implement policy that moves from a reactive response to a more proactive approach focusing on preparedness. These and other questions should become a central focus for scholars and emergency planning.

William Donner is an assistant professor of sociology at Indiana University of Pennsylvania. His areas of expertise include the social demographics of hazard epidemiology, environmental sociology, sociology of risk and risk perception, quantitative research methods, social inequality, and social theory. Havidán Rodríguez is provost and vice president for Academic Affairs for the University of Texas-Pan American. He previously was at the University of Delaware, where he was deputy provost and director of the Disaster Research Center, the oldest and one of the world’s leading social science centers in this field.


  1. Ben Wisner et al., At Risk: Natural Hazards, People's Vulnerability, and Disasters, 2d ed. (London: Routledge, 2004).
  2. Charles Perrow, The Next Catastrophe (Princeton, NJ: Princeton University Press, 2007).  
  3. Quijia Zou et al., "Prediction Research on the Economic Losses and Population Casualties of Earthquake Disasters," unpublished manuscript (Beijing: Institute of Geophysics, State Seismological Bureau, 1992).
  4. William Donner and Havidán Rodríguez, "Population Composition, Migration, and Inequality: The Influence of Demographic Changes on Disaster Risk and Vulnerability," Social Forces 87, no. 2 (2008): 1089-1114.
  5. Havidán Rodríguez et al., "A Snapshot of the 2004 Indian Ocean Tsunami: Societal Impacts and Consequences," Disaster Prevention and Management 15, no. 1 (2006): 163-77.
  6. Benigno Aguirre, "The Lack of Warnings Before the Saragosa Tornado," International Journal of Mass Emergencies and Disasters 6, no. 1 (1988): 65-74.
  7. Elaine Enarson and Betty H. Morrow, "A Gendered Perspective: The Voices of Women," in Hurricane Andrew: Ethnicity, Gender, and The Sociology of Disasters, ed. W.G. Peacock, B.H. Morrow, and H. Gladwin (Miami: International Hurricane Center, Laboratory for Social and Behavioral Research, 2000): 116-37.
  8. Havidán Rodríguez, Rogelio Sáenz, and Cecilia Menjívar, eds., Latinas/os in the United States: Changing the Face of America (New York: Springer, 2008).
  9. Alice Fothergill, and Lori Peek, "Poverty and Disasters in the United States: A Review of Recent Sociological Findings," Natural Hazards 32, no. 1 (2004): 89-110.
  10. Ben Wisner and Peter Walker, "Katrina and Goliath," Humanitarian Practice Network, accessed at www.odihpn.org/report.asp?id=2773, on Feb. 13, 2007; Rodríguez et al., "A Snapshot of the 2004 Indian Ocean Tsunami: Societal Impacts and Consequences"; and David L Brunsma, David Overfelt, and Steve J. Picou, eds., The Sociology of Katrina: Perspectives on a Modern Catastrophe, 2d ed. (New York: Rowman & Littlefield, 2010): 25-36; and Robert D. Bullard and Beverly Wright, "Race, Place, and the Environment in Post-Katrina New Orleans," in Race, Place and Environmental Justice After Hurricane Katrina: Struggles to Reclaim, Rebuild, and Revitalize New Orleans and the Gulf Coast, ed. Robert D. Bullard and Beverly Wright (Denver: Westview Press, 2009): 19-48.
  11. Havidán Rodríguez and Carla Russell, "Understanding Disasters: Vulnerability, Sustainable Development, and Resiliency,” in Public Sociologies Reader, ed. Judith Blau and Keri Iyall-Smith (New York: Rowman & Littlefield, 2006): 193-211.
  12. Elaine Enarson and Betty H. Morrow, "Why Gender? Why Women? An Introduction to Women and Disaster," in The Gendered Terrain of Disaster: Through Women’s Eyes, ed. Elaine Enarson and Betty H. Morrow (Westport, CT: Praeger, 1998).
  13. Brenda Phillips and Maureen Fordham, "Introduction," in Social Vulnerability to Disasters, ed. Brenda D. Phillips et al. (New York: CRC Press, 2010): 1-23.