How Urbanization is Affecting Natural Disaster Risk Assessment

hazardsThe United Nations Population Fund predicts that by the year 2050 86% of the population in developed nations (64% in developing nations) will live in urban areas. This ongoing migration from rural areas to more densely inhabited cities catalyzes urban sprawl, which subsequently makes a greater portion of the population susceptible to the risks of natural disasters.

The Global Facility for Disaster Reduction and Recovery (GFDRR) examines this dynamic and its relationship to disaster risk assessment in their recently released report The Making of a Riskier Future: How Our Decisions are Shaping Future Disaster RiskA few of the document’s key points are summarized below as well as in this short GFDRR video.

  • Population increase and climate change are the largest driving factors of urbanization. Worldwide, “up to 1.4 million people are moving into cities every week, with up to 90 percent [of this migration] happening in Africa and Asia.”
  • Wealthy nations, companies, and citizens employ resources to adequately prevent natural disasters from inflicting catastrophic damage, whereas their impoverished counterparts lack the ability to do so. The report cites global flooding as an example: “in the last 20 years, low-income countries experienced just over a quarter of floods, but bore nearly 90 percent of related casualties.”
  •  “[G]lobal losses from disasters have nearly quadrupled over the last few decades, from an average of $50 billion per year in the 1980s to close to $200 billion per year over the past decade.”
  • The three main components to natural disaster risk assessment are (1) hazard or the type of disaster (earthquake, hurricane, etc.); (2) exposure, which refers to a population’s layout and economic ability to mitigate the effects of a natural disaster; and (3) vulnerability, which refers to “the susceptibility of the exposed elements to the natural hazard.”
  • The majority of natural disaster risk assessment evaluates the potential effects of a disaster at any given time, and is thus termed ‘static’. The report argues that “All three of [the aforementioned] components are dynamic, and change over time under natural and human conditions,” thus disaster risk assessment should adapt appropriately to evaluate the three components dynamically.
  • In addition to dynamic risk assessment, regions committed to the following programs will be best prepared to mitigate the effects of natural disasters:
    • Hazard:  Climate Change Mitigation, Urban Design, and Resource Planning
    • Vulnerability: Urban Planning/Construction and Social Safety Nets
    • Exposure: Land-Use Planning and Managed Urban Expansion

For more resources on Climate Change, Earthquakes, Hurricanes, and Wildfires, visit the Homeland Security Digital Library (some documents may require HSDL login).