Much of the destruction caused by natural disasters is avoidable.© Punchstock

As Monday's earthquake off Indonesia painfully illustrated, natural disasters often strike the same place repeatedly. Researchers have now ascertained the areas that are most at risk, in a study that could help countries and aid agencies plan for future catastrophes.

There have been other efforts to assess disasters, such as the publicly available database maintained by the Center for Research on the Epidemiology of Disasters (CRED) in Brussels. These have consisted essentially of historical records of disasters grouped by country.

But past data alone cannot predict future disasters. And these simple data sets do not reflect different countries' population densities and wealth, which affect their vulnerability, says Maxx Dilley of Columbia University in New York, the lead author of the new study.

Dilley and colleagues at the World Bank broke down the most of the globe into 8 million grid cells of about 25 square kilometres each. They then mapped the risks of human and economic damage from six types of disaster, such as cyclones and landslides, on to each one and built up a picture of the world's most exposed places¹.

The world's most vulnerable countries include Bangladesh, Nepal, Burundi, Haiti and Taiwan. In these places, more than 90% of people are at 'high risk' of death for two or more types of disaster. The researchers define high-risk areas as having the top 30% of risk compared with other areas of the world.

Although many of these areas were already known to be in danger, the report provides a more sophisticated way to compare risks across countries and regions, allowing governments and aid agencies to prioritize their resources, says Maryvonne Plessis-Fraissard, director for transport and urban development at the World Bank. "Before, we did not have that big picture," she says.

Developing a solution

Much of the damage and death that disasters cause is preventable: by building earthquake-proof structures, for example. But repeated hits lock many of the world's developing countries into a cycle that makes it difficult to fund changes, especially as much aid goes into immediate relief efforts.

The World Bank plans to use its hotspot map to identify those countries most in need and help them implement a preventive, rather than reactive, approach to disasters.

Its approach is already affecting homeowners in Turkey, who must weather frequent earthquakes. When providing aid, the World Bank requires them to buy insurance for their homes. This shifts the responsibility for safe buildings from the government to the individual and private-sector insurance companies.

The World Bank also intends to encourage governments to invest in measures such as flood embankments and cyclone shelters by granting loans to countries who plan for disasters. Countries have already started to request money specifically for risk management, indicating that the message is getting through, says Plessis-Fraissard.

"We must stop making it more complicated than it is," argues Debarati Guha-Sapir, director of CRED, in response to advocates of new technologies. "If you want to reduce problems after disasters, you just have to protect people by giving them better housing, better education and better health services." 

Center for Research on the Epidemiology of Disasters, Brussels

• References

  1. Dilley M., Chen R. S., Deichmann U., Lerner-Lam A. L. & Arnold M. Natural Disaster Hotspots: A Global Risk Analysis, http://publications.worldbank.org/
     ecommerce/catalog/product?item_id=4302005 ( World Bank,2005).