By Aditi Hate – Herbert Saffir, who passed away last month, created the Saffir-Simpson hurricane intensity scale in 1969, still used as the accepted measure for determining hurricane strength. Saffir’s pioneering efforts have been followed by improvements in US capacity to provide accurate and timely predictions about the likelihood and impact of hurricanes as well as other natural disasters. Today, experts can better estimate the levels of storm surge and flooding that would follow a major hurricane or when and where tsunamis may occur after a large-scale earthquake.
The US, however, still faces major challenges in improving its ability to act upon natural disaster warnings and effectively implement appropriate protective actions to further reduce the risks to vulnerable communities. The effective use of public communications systems to quickly disseminate early warnings and implement protective actions in such communities is one such challenge.
Hurricane Katrina’s impact on the Gulf Coast illustrated the gap between prediction and protective actions. Prior to Katrina’s Gulf Coast landfall, Federal, state, and local government officials knew that a category 3, 4, or 5 hurricane could cause the New Orleans levee system to fail and inundate the city with over twenty feet of water.  However, the mechanisms for implementing and communicating protective actions to the public after receiving warning of an approaching hurricane remained underdeveloped. This delayed evacuations, especially of residents who either could not evacuate the area independently or did not evacuate voluntarily because they were unaware of the magnitude of the impending storm’s impact on the city.
Since Hurricane Katrina, Federal, state, and local government agencies have improved their disaster preparedness capabilities. Many jurisdictions have identified protective actions that would be necessary to reduce the risk to life and property in a natural disaster. These jurisdictions have also strengthened their citizen preparedness programs through disaster training workshops and exercises so that their citizens are better prepared for the next major disaster.
Still, natural disasters rarely provide much, if any, forewarning to state and local governments traditionally responsible for communicating early warnings and protective actions to the public. Consequently, jurisdictions need to have pre-established mechanisms on hand so that they can swiftly implement the appropriate protective actions that will reduce the risk to life and property. An effective public communications system that alerts residents about the magnitude of an impending disaster and helps implement protective actions prior to the disaster is an essential element of these mechanisms.
Public communications, however, remains one of the greatest challenges that jurisdictions will face when the next disaster strikes. This challenge is compounded by how some jurisdictions’ disaster plans have approached public communications during a major disaster. Jurisdictions too often base their warning plans on how they assume the public ought to react during a disaster. This approach ignores the potential that some of the threatened population may not react to emergency warnings in a calm and orderly manner.
All levels of government, especially states and localities, need to continue to refine and improve their emergency warning and public communications processes for disasters. This requires a greater effort for understanding how the public, especially particular communities, are likely to respond to emergency warnings issued by the government. For example, more than two years after Hurricane Katrina, government officials possess a very limited understanding of how vulnerable populations, including specific special needs communities, interpret and respond to disaster warnings. The Federal government, especially the Departments of Health and Human Services and Homeland Security, should advance an aggressive research program that can ultimately provide the knowledge that serves as the foundation for realistic state and local emergency warning and communications plans. This will, thus, enable jurisdictions to issue clear and authoritative instructions that warn the public and give them enough time to undertake actions necessary to protect themselves and their families before the next disaster strikes their communities. It will also help reduce panic and allow disaster preparedness operations to be conducted more effectively.
 “In 2000, the U.S. Army Corps of Engineers’ (USACE) modeled the effects of a slow moving Category 4 or any Category 5 hurricane on the gulf coast region. The USACE estimated that the city of New Orleans would experience significant flooding up to twenty feet of water if such a hurricane took a “critical path” towards the city. In addition, a weaker, slow moving hurricane would be as dangerous as a more powerful, faster moving storm because it would generate as much or more flooding by dropping more rainfall. In 2002, Vice Admiral Conrad C. Lautenbacher, Jr., Undersecretary of Commerce for Oceans and Atmosphere, confirmed that a Category 3, 4 or 5 hurricane could cause the overtopping of New Orleans’ levees and subsequent flooding of the city.” The Executive Office of the President, The Federal Response to Hurricane Katrina: Lessons Learned (February 2006), 24.
Aditi Hate is a Research Assistant for the Domestic Preparedness and Homeland Security program at the Stimson Center.