Legacy effects of redlining on the distribution of greenspaces in US cities
Data files
Apr 01, 2026 version files 79.78 MB
-
Gallo_etal_FEE_2026.zip
79.76 MB
-
README.md
14.65 KB
Abstract
We investigated how a discriminatory housing policy – redlining – has shaped the spatial patterns and configurations of greenspaces throughout 177 U.S. cities. Housing segregation has been a long-term development practice that has sequestered communities of color to areas with heightened environmental and public health risks. While the lasting environmental, social, and economic impacts of redlining are clear, the impact of redlining on landscapes are still unfolding. We found that neighborhoods that were historically redlined have less greenspace and that individual greenspaces were smaller and less connected. We also found that residents living in these neighborhoods with less greenspace were predominantly communities of color and/or had lower income. Thus, the legacy of redlining can be seen in the modern spatial patterns of urban greenspaces, and ecosystem services provided by greenspaces have been systematically absent from redlined communities for decades.
The following data files, R scripts, and Supporting Documents are found in Gallo_etal_FEE_2026.zip
Authors
Travis Gallo1, Mason Fidino2, Chris Schell3, Marccus Hendricks1, Seth Magle2
- University of Maryland
- Lincoln Park Zoo, Chicago
- University of California, Berkley
Abstract
We investigated how a discriminatory housing policy – redlining – has shaped the spatial patterns and configurations of greenspaces throughout 177 U.S. cities. Housing segregation has been a long-term development practice that has sequestered communities of color to areas with heightened environmental and public health risks. While the lasting environmental, social, and economic impacts of redlining are clear, the impact of redlining on landscapes are still unfolding. We found that neighborhoods that were historically redlined have less greenspace and that individual greenspaces were smaller and less connected. We also found that residents living in these neighborhoods with less greenspace were predominantly communities of color and/or had lower income. Thus, the legacy of redlining can be seen in the modern spatial patterns of urban greenspaces, and ecosystem services provided by greenspaces have been systematically absent from redlined communities for decades
File Descriptions
To conduct this analysis you will have to download the publicly available shapefile from the Mapping Inequality project (https://dsl.richmond.edu/panorama/redlining/data).
The shapefile that we used for the entire U.S. is no longer available as a single shapefile. The full U.S. data can be downloaded as a GeoPackage or GeoJSON file and processed or
the shapefiles can be downloaded city by city and combined at the link provided above.
To use 2026-01-12_data_processing.R you will also need to download all of the publicly available GIS data.
Links to the url that we used to download each publicly available data layer is provided within the script that they are called.
Data File:
2023-03-02_processed_dataframe.rds: this dataframe is the results of 2026-01-12_data_processing.R and can be called into 2026-01-12_model_fit.R to fit models.
This data has 43 variables and 10588 observations. Each row is a polygon (feature) from the Mapping Inequality HOLC shapefile used in this analysis.
| Column header | Data type | Description | |
|---|---|---|---|
| state | character | The abbreviation of the state of the respective observation (from original HOLC shapefile) | |
| city | character | The city of the respective observation (from original HOLC shapefile) | |
| name | character | The neighborhood name give from the original HOLC map (from original HOLC shapefile) | |
| holc_id | character | The individual polygon's ID from original HOLC map (from original HOLC shapefile) | |
| holc_grade | character | The HOLC grade (A,B,C,D) from original HOLC map (from original HOLC shapefile) | |
| neighborho | integer | The neighbor hood ID from original HOLC map (from original HOLC shapefile) | |
| city_ID | character | Combination of state and city combined with "-" to make a unique city ID | |
| layer | numeric | Unused variable created during a spatial join | |
| level | character | Unused variable created during a spatial join | |
| class | numeric | Unused variable created during a spatial join | |
| id | integer | Unused variable created during a spatial join | |
| area_mn | numeric | Mean area of greenspace patches calculated for each HOLC polygon using landscapemetrics in 2026-0-12_data_processing.R |
|
| core_mn | numeric | Mean core habitat calculated for each HOLC polygon using landscapemetrics in 2026-0-12_data_processing.R |
|
| mesh | numeric | Effective mesh size (ha) calculated for each HOLC polygon using landscapemetrics in 2026-0-12_data_processing.R |
|
| np | numeric | Number of patches calculated for each HOLC polygon using landscapemetrics in 2026-0-12_data_processing.R |
|
| para_mn | numeric | Mean perimeter to area ratio calculated for each HOLC polygon using landscapemetrics in 2026-0-12_data_processing.R |
|
| cells_1 | numeric | The number of raster cells overlapping the respective polygon that was categorized as greenspace in 2026-0-12_data_processing.R |
|
| cells_0 | integer | The number of raster cells overlapping the respective polygon that was categorized as not greenspace in 2026-0-12_data_processing.R |
|
| number_of_cells | integer | The total number of raster cells that overlap the respective polygon in 2026-0-12_data_processing.R |
|
| prop_greenspace | numeric | The proportion of raster cells that are categorized as greenspace (cells_1/cells_0) calculated for each HOLC polygon in 2026-0-12_data_processing.R |
|
| STUSPS | character | State abbreviation relic from spatial join | |
| NAME | character | Full name of state relic from spatial join | |
| city_popdens | numeric | The population density summed across all 2020 census block-levels within the city extent from 2020 census block-level data in 2026-0-12_data_processing.R |
|
| STUSPS | character | State abbreviation relic from spatial join | |
| income | numeric | The mean median household income for each HOLC polygon calculated in 2026-0-12_data_processing.R using U.S. Census 2021 American Community Survey block group data |
|
| rent | numeric | Mean gross rent for each HOLC polygon calculated in 2026-0-12_data_processing.R using U.S. Census 2021 American Community Survey block group data |
|
| income_scaled | numeric | Median household income divided by mean gross rent calculated in 2026-0-12_data_processing.R |
|
| Total | numeric | The total population calculated for each HOLC polygon using U.S. Census 2020 block level data calculated in 2026-0-12_data_processing.R |
|
| White | numeric | The total White-alone population calculated for each HOLC polygon using U.S. Census 2020 block level data calculated in 2026-0-12_data_processing.R |
|
| Black | numeric | The total Black or African American alone population calculated for each HOLC polygon using U.S. Census 2021 American Community Survey block group data calculated in 2026-0-12_data_processing.R |
|
| Hispanic | numeric | The total Hispanic or Latino Origin population calculated for each HOLC polygon using U.S. Census 2020 block level data calculated in 2026-0-12_data_processing.R |
|
| total_new | numeric | Total divided by the proportion of the census block overlapping the respective HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| white_new | numeric | White divided by the proportion of the census block overlapping the respective HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| black_new | numeric | Black divided by the proportion of the census block overlapping the respective HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| latinx_new | numeric | Hispanic divided by the proportion of the census block overlapping the respective HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| Total_density | numeric | Total divided by the area of the HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| White_density | numeric | White divided by the area of the HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| Black_density | numeric | Black divided by the area of the HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| Hispanic_density | numeric | Hispanic divided by the area of the HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| total_new_density | numeric | total_new divided by the area of the HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| white_new_density | numeric | white_new divided by the area of the HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| black_new_density | numeric | black_new divided by the area of the HOLC polygon calculated in 2026-0-12_data_processing.R |
|
| latinx_new_density | numeric | latinx_new divided by the area of the HOLC polygon calculated in 2026-0-12_data_processing.R |
R Scripts:
2026-01-12_data_processing.R: will process the Mapping Inequality HOLC shapefile and prepare the data for 2023-03-01_model_fit.R
2026-01-12_model_fit.R: will use the results form 2023-03-01_data_processing.R to fit Bayesian models to each response variable using NIMBLE.
2026-01-12_Plotting_Landscape_Results.R: is used to make the first panel in Figure 2 plotting the landscape metric results
2026-0-12_PlottingDemographyResults.R: is used to create the second panel in Figur 2 plotting the demographic results
DBDA2E-utilities.R and package_load.R are utility scripts with various functions used throughout the analyses
SummaryScripts.R: script to calculate various summary statistic
Supporting Documents:
CitySpecificModelResults.pdf: this supporting document plots the 95% credible intervals of city-specific posterior distributions for each response variable
as a function of HOLC category. Each page contains a city with a 5-panel plot containing the model results
for each response variable.
CitySpecificModelResults-colorblindFriendly.pdf: this is a colorblind friendly version of CitySpecificModelResults.pdf
Historic Home Owner Loan Corporation scans and digitized maps are publicly available at the Mapping Inequality website: https://dsl.richmond.edu/panorama/redlining/data
All data was processed using R ver 4.3.2.
