Environmental Public Health Tracking: Community Characteristics Data

Community characteristics are a description of the area around us. They can include information about an area's natural features, such as how much land is covered by forests or water, and its human-made features from types of housing and roads to locations of hospitals, schools, or other public service buildings. We track community characteristics because they can help us identify and respond to threats and hazards before they cause harm. Community characteristics have strong implications for the resilience of a community.

Explore definitions and explanations of terminology found on this page, like age-adjusted rate and confidence intervals.

Frequently asked questions

Understanding the characteristics of a community is important for public health practices such as program planning and epidemiologic studies. Community characteristics are particularly important in public health emergency preparedness.

A key step in preparedness planning for any disaster, whether it be radiological, chemical, or natural, is identifying a community's

Most common hazards
Most vulnerable populations
Available resources
Ability to respond

Understanding local infrastructure, vulnerabilities, and resource availability allows public health professionals to quickly establish priorities and take action during the emergency or disaster response.

Community characteristics data on the portal currently include types of housing and households; how many homes are located in flood zones; number of people or households with access to internet; whether an area is urban or rural; and whether land is developed, used for agriculture, or covered by forest. Additional community characteristics indicators and measures will be added as they become available.

By tracking these community characteristics we are better able to:

Identify threats, hazards, and at-risk populations
Evaluate potential impact of threats or hazards within the context of a community's population, climate, built environments, infrastructure, and resources
Determine potential resource needs and public health actions which could lessen or prevent sickness, injury, or death in the event of a public health emergency

Flood vulnerability

Federal Emergency Management Agency (FEMA) - National Flood Hazard Layer
Landscan USA Nighttime population estimates

Households

American Community Survey 5-year Estimates

Internet use

American Community Survey 5-Year Estimates. All data for this indicator are derived from the U.S. Census Bureau, American Factfinder site.

Land cover

Data are derived from Multi-Resolution Land Characteristics (MRLC) National Land Cover Database

Land use

Please note that not all topics are available at both the census tract and county geographies.

Flood Vulnerability
- Number of housing units within FEMA designated flood hazard area
- Number of people within FEMA designated flood hazard area
- Number of square miles within FEMA designated flood hazard area
- Percent area (square miles) within FEMA designated flood hazard area
- Percent of hospital beds within flood hazard area
- Percent of hospitals within flood hazard area
Households
- Number of housing units
- Number of housing units with 10 or more units
- Number of housing units with more people than rooms
- Number of housing units with no vehicle available
- Number of mobile-home housing units
- Number of people living in group quarters
- Number of renter-occupied housing units
- Number of vacant housing units
- Percent of housing units with 10 or more units
- Percent of housing units with more people than rooms
- Percent of housing units with no vehicle available
- Percent of mobile home housing units
- Percent of renter-occupied housing units
- Percent of vacant housing units
- Percent population living in group quarters
Internet Access
- Number of households with a smartphone
- Number of households with a smartphone, but no other device
- Number of households with income less than $20,000 without an internet subscription
- Number of households with no internet access
- Number of people age 25+ years, with low education who have a computer without internet subscription
- Number of people age 65+ years who have a computer without internet subscription
- Number of people with access to a computer with internet, but no cell phone
- Number of unemployed people aged 16+ years who have a computer without internet subscription
- Percent of households with a smartphone
- Percent of households with a smartphone, but no other device
- Percent of households with income less than $20,000 without an internet subscription
- Percent of households with no internet access
- Percent of people age 25+ years, with low education who have a computer without internet subscription
- Percent of people age 65+ years who have a computer without internet subscription
- Percent of people with access to a computer with internet, but no cell phone
- Percent of unemployed people aged 16+ years who have a computer without internet subscription
Land Cover
- Average percent of developed imperviousness
- Percent of land covered by forest
- Percent of land covered by water
Land Use
- Classification of county from rural to urban (six category scale)
- Classification of county from rural to urban (two category scale)
- Percent of land used for agriculture
- Percent of land used for development

There are numerous considerations to keep in mind when interpreting the data. Please visit the CDC (Centers for Disease Control and Prevention) National Tracking Program Indicators and Data webpage for additional information.

Select the content area from the drop down list, for example: Community Characteristics. Then select the specific indicator you are interested in from the drop down list, for example, "Flood Vulnerability."

Click the link below to download the data you're looking for:

Census Tract Data (CSV)

County Data (CSV)

Community characteristics data details

Flood vulnerability

Number of housing units within FEMA designated special flood hazard area (SFHA)

These data provide estimates of the number of housing units within the SFHA. The SFHAs have 1% annual chance of coastal or riverine flooding. The population distribution was derived using 2010 census block group data in conjunction with 2010 LandScan Nighttime Population raster dataset (Bhaduri, et al., 2007), aggregated to the county level using a Geographic Information System (GIS). The ratio of population distribution was used to determine housing unit distribution at census block group level, which was then aggregated to the county level. The 2011 National Flood Hazard Layer, a national-level digital flood hazard database created by Federal Emergency Management Agency (FEMA), was used to calculate the flood hazard area.

Number of people within FEMA designated special flood hazard area (SFHA)

These data provide estimates of the number of people within the SFHA. The SFHAs have 1% annual chance of coastal or riverine flooding. In order to estimate population, 2010 census block group data (assuming uniform population distribution among counties) were overlaid with the digital coastal flood hazard database using a Geographic Information System (GIS). Additionally, census block group-level measures were derived from the 2010 LandScan Nighttime Population raster dataset and aggregated to the county level. The 2011 National Flood Hazard Layer, a national-level digital flood hazard database created by Federal Emergency Management Agency (FEMA), was used to calculate the flood hazard area.

Number of square miles within FEMA designated special flood hazard area (SFHA)

These data provide areal (square miles) estimates of the SFHA with a 1% annual chance of coastal or riverine flooding, per county. This is sometimes referred to as the “100 year” flood zone. The 2011 National Flood Hazard Layer, a national-level digital flood hazard database created by Federal Emergency Management Agency (FEMA), was used to calculate the flood hazard area.

Percent area (square miles) within FEMA designated special flood hazard area (SFHA)

These data provide county estimates of the percentage of total area within the SFHA. The SFHAs have 1% annual chance of coastal or riverine flooding. The 2011 National Flood Hazard Layer, a national-level digital flood hazard database created by Federal Emergency Management Agency (FEMA), was used to calculate the flood hazard area.

Percent of hospital beds within a flood hazard area

Hospital data were obtained from the 2016 American Hospital Association (AHA) Annual Survey. A Geographic Information System (GIS) was used to identify hospitals within a Federal Emergency Management Agency (FEMA)-designated flood hazard zone. The National Flood Hazard Layer (NFHL) does not have national coverage. Therefore, percentage of hospital beds in flood hazard areas is not available for all counties.

Percent of hospitals within a flood hazard area

Households

Number of housing units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Number of housing units with 10 or more units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Number of housing units with more people than rooms

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Number of housing units with no vehicle available

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Number of mobile homes housing units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Number of population living in group quarters

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Number of renter-occupied housing units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Number of vacant housing units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Percent of housing units with more people than rooms

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Percent of housing units with no vehicle available

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Percent of mobile homes housing units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Percent of renter-occupied housing units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Percent of vacant housing units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Percent of vacant housing units

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.

Percent of population living in group quarters

Data provided by the U.S. Census Bureau, American Factfinder, American Community Survey (ACS) five-year estimates. Read more about the Census ACS methodology.