Neighborhoods at Risk is a free, interactive data tool that provides neighborhood-level (by census tract) information about potentially vulnerable people and climate change. The tool allows users to filter and explore census tracts based on 13 socioeconomic and climate exposure variables. It also provides climate projections for changes in temperature and precipitation for the selected location. Users can download customized reports showing socioeconomic data for selected census tracts.

People. Neighborhoods at Risk uses census tract-level socioeconomic data from the latest release of the U.S. Census American Community Survey (ACS) 5-year estimates. Headwaters Economics updates Neighborhoods at Risk with newly released data from the U.S. Census Bureau’s American Community Survey within 90 days after data publication. This page shows the update frequency and timing.

Neighborhoods at Risk displays nine socioeconomic variables and filters about people. For each characteristic, the tool provides a margin of error as reported by the Census. Data include:

• Children under 5 years old
• Families in poverty
• Households with no car
• Housing units that are rentals
• People of color including Hispanics
• People over 65 years old
• People who don’t speak English well
• People with disabilities
• People without health insurance

Climate exposure. Neighborhoods at Risk uses national data to calculate the area in each census tract with climate exposure. There are four climate exposure variables: 

• Properties with flood risk. Values represent the percent of properties affected by a storm resulting in severe flooding (a 1-in-100 year flood event). This type of event has a 26% chance of occurring at least once over the life of a 30-year mortgage. Data are from First Street Foundation.
• Area in hurricane flood zone. This is defined as the average percent of area inundated by storm surge in the event of a Category 3 hurricane in 2018. Data are from First Street Foundation. 
• Area lacking tree canopy. Data are based on remotely sensed, 30-meter tree canopy estimates from 2016 via the National Land Cover Dataset, housed by the Multi-Resolution Land Characteristics Consortium.  
• Area of impervious surface. Data are based on remotely sensed, 30-meter urban impervious surfaces from 2019 via the National Land Cover Dataset, housed by the Multi-Resolution Land Characteristics Consortium. 
• Area in 500-year floodplain. This is defined as the percent of area that intersects with the 500-year floodplain, which includes all 100-year floodplain areas. Data are from FEMA. 

Climate projections. Neighborhoods at Risk uses climate projection data from the Northeast Regional Climate Center’s Applied Climate Information System representing LOCA Scenarios developed for the Fourth National Climate Assessment. There are four climate projections variables:

• Days per year above 90°F/95°F/100°F.
• Average annual temperature.
• Days per year with precipitation above 1″/2″/4″.
• Average annual precipitation.

Precipitation includes rainfall and snowfall equivalent. As a rule of thumb, ten inches of fallen snow is estimated to contain roughly one inch of water, but this number can vary greatly depending on snow density.

People

To cite data about people and socioeconomic conditions found in the Neighborhoods at Risk web application and report, Headwaters Economics recommends that you use the following citation: 

U.S. Department of Commerce. 2019. Census Bureau, American Community Survey Office, Washington, D.C., as reported by Headwaters Economics’ Neighborhoods at Risk. Retrieved [date] from https://headwaterseconomics.org/apps/neighborhoods-at-risk/

Climate Exposure

To cite climate exposure data found the Neighborhoods at Risk web application, Headwaters Economics recommends that you use the following citations:  

Properties with Flood Risk

First Street Foundation. (2022). FloodFactor Model Methodology https://firststreet.org/research-lab/published-research/flood-model-methodology_overview/, as reported by Headwaters Economics’ Neighborhoods at Risk. Retrieved [date] from https://headwaterseconomics.org/apps/neighborhoods-at-risk/

Hurricane Flood Zone

Porter J, Lewis-Gruss S, Freeman N, Chu Z. (2018). First Street Foundation Coastal Tidal and Surge Flood Model Technical Methodology https://firststreet.org/flood-lab/research/methodology/, as reported by Headwaters Economics’ Neighborhoods at Risk. Retrieved [date] from https://headwaterseconomics.org/apps/neighborhoods-at-risk/  

500-year Floodplain

FEMA National Flood Hazard Layer (NFHL). (2018). Flood Risk Database (FRD) Technical Reference https://www.fema.gov/national-flood-hazard-layer-nfhl, as reported by Headwaters Economics’ Neighborhoods at Risk. Retrieved [date] from https://headwaterseconomics.org/apps/neighborhoods-at-risk/  

Tree Canopy and Impervious Surface

Homer CG, Dewitz JA, Jin S, Xian G, Costello C, Danielson P, Gass L, Funk M, Wickham J, Stehman S, Auch RF, Ritters KH. (2020). Conterminous United States land cover change patterns 2001–2016 from the 2016 National Land Cover Database. ISPRS Journal of Photogrammetry and Remote Sensing, 162, 184-199, at https://doi.org/10.1016/j.isprsjprs.2020.02.019, as reported by Headwaters Economics’ Neighborhoods at Risk. Retrieved [date] from https://headwaterseconomics.org/apps/neighborhoods-at-risk/

Climate Projection

To cite climate projection data found in the Neighborhoods at Risk web application, Headwaters Economics recommends that you use the following citations:   

Northeast Regional Climate Center. (n.d.). Applied Climate Information System (ACIS). Ithaca, NY: Cornell University. Retrieved from http://rcc-acis.org

DeGaetano AT, Noon W, Eggleston KL. (2015). Efficient Access to Climate Products using ACIS Web Services. Bulletin of the American Meteorological Society, 96(2), 173-180. Retrieved from http://journals.ametsoc.org/doi/10.1175/BAMS-D-13-00032.1

The nine characteristics and filters included under “People” in Neighborhoods at Risk are indicators of populations that are potentially more vulnerable to climate risk and climate-related disasters. Not all people who fit these criteria are more vulnerable, but research shows that these populations are, on average, more likely to experience difficulty during all phases of climate-related disasters including:

• Mitigation: reducing the potential risk
• Preparedness: getting plans and resources ready
• Response: protecting and rescuing
• Recovery: rebuilding

The downloadable Neighborhoods at Risk report provides detailed information and references documenting how each variable is associated with potentially higher risk to climate change.

The four characteristics and filters included under “Climate Exposure” in Neighborhoods at Risk are indicators of land area that may experience more significant impacts from climate change. These variables (hurricane flood zones, floodplains, impervious surface, and lack of tree canopy) represent characteristics of our physical environment that make us more or less vulnerable to climate change by affecting the likelihood of extreme heat and flood events.

When you first view Neighborhoods at Risk, the application shows only the three “People” variables that are most significant for the selected place. To identify the top three variables, all nine “People” variables are ranked against all other places in the United States. By default, the tool will show only the three that rank highest for the selected location, but users can change these variables by selecting the “see more” button. To account for ties in ranks and locations with missing data, the ranks are normalized by dividing by the maximum rank for that variable across the entire U.S.