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Billion-Dollar Disasters: Mapping Vulnerabilities with Census Tract-Level Data

Aerial view of a wildfire line moving through a forest with large clouds of smoke being emitted above the fire.
Courtesy of the National Park Service

The NCEI Billion-Dollar Disaster and Risk Mapping tools now include U.S. Census tract data, expanding on FEMA’s National Risk Index to provide an integrated view of U.S. hazard risk, exposure, and vulnerability across more than 100 combinations of weather and climate hazards.    

These enhanced interactive maps provide data for over 72,000 U.S. Census tracts, which are small subdivisions of counties that average about 4,000 inhabitants. Users can now visualize combined physical exposure, socioeconomic vulnerability, and markers of resilience to natural hazards on a finer scale than ever before.

Assessing Compound Hazard Risk

These new maps enhance the NOAA Billion-Dollar Weather and Climate Disaster website by producing interactive U.S. Census tract-level, multi-hazard risk maps for any combination of hazard risk, complementing the county-level maps released in December 2021. These hazards include severe storms (tornado, hail, damaging winds), drought events and heat waves, hurricanes and tropical storms, wildfires, river-basin and urban flooding, winter storms, and freeze events and cold waves.

For example, a user can explore compound hazard risk such as the cascading impacts of drought, wildfire, and flooding that can occur across the U.S. Southwest. Or, one might examine how hurricane, flooding, and severe storm events across the Gulf coast have severely impacted vulnerable populations.

GOES-East visible satellite image of a strong hurricane Ida making landfall on the Gulf coast of the U.S. on August 29, 2021.
Hurricane Ida makes landfall on the Gulf coast of the U.S. on August 29, 2021.

 

Mapping Socioeconomic Vulnerability

The new maps also provide select socioeconomic vulnerability information using the CDC Social Vulnerability Index, which is derived from the U.S. Census Bureau’s American Community Survey data. There are numerous factors found in the Census tract data that can indicate potential vulnerability, including: 

  • Socioeconomic status (below poverty level, low income, no high school diploma)
  • Household composition and disability (age 65 or older, age 17 or younger, older than age 5 with a disability, single-parent households)
  • Minority status and language (minority, speak English “less than well”)
  • Housing type and transportation (mobile homes, no vehicle)

Helping Users Make Informed Decisions

This new information has the potential to inform and guide hazard preparation and mitigation for homeowners, community planners, and emergency managers. It also encourages community-level risk communication and planning, and could guide communities’ building codes and standards, making physical infrastructure more resilient to disasters. Finally, the availability of the Census-tract level data can better inform long-term disaster resilience and recovery plans.

Map of North Carolina divided into U.S. Census tracts that are shades of yellow. Darker yellow indicates higher risk and is found mostly in coastal tracts, while lighter yellow indicates lower risk and is found more inland.
Tropical Cyclone Risk mapped for North Carolina counties in the Billion-Dollar Disasters dashboard from NOAA NCEI.

 

Examining this information can help to identify areas where both risk exposure and socioeconomic vulnerability is very high. Decision-makers can then use this information to better understand where to focus hazard mitigation planning and investment, especially in areas where resources are sparse.

“This new census tract information, joining the county data, is another important addition to NCEI’s U.S. Billion-Dollar Disasters site,” said Adam Smith, Billion-Dollar Disaster expert for NOAA NCEI. “This will allow for community-level awareness of a population’s risk and vulnerability to the extreme weather and climate disasters that routinely strike the nation.”

More Frequent Billion-Dollar Disasters

This new mapping tool comes at a time when the number and cost of billion-dollar disasters in the U.S. is rising. Since January of 2020, the nation has experienced 51 separate billion-dollar weather and climate disasters, totalling more than $275 billion in damages and killing nearly 1,000 people. Through June 2022, the U.S. has already been impacted by nine separate billion-dollar disasters, a busy start to the year.

View the interactive enhanced state and county-level maps on NOAA’s Billion-Dollar Disasters website.