Sources

The Sprawling of Atlanta project uses aerial images and census data from a variety of sources. Below is a list of sources for each data layer by year.

1938-1943 aerial mosaic layer:

All aerials for this layer come from the University of Georgia Map and Government Information Library, Aerial Photography Collection. This layer is a blend of United States Department of Agriculture (USDA) aerial images taken in 1938, 1940, 1942 and 1943. Some aerial photographs were missing. Therefor, this layer is partially incomplete.

1940 census tract population and housing layers:

The census data for this layer comes from the 1940 Decennial Census accessed via Social Explorer. Census tracts in 1940 only covered parts of Fulton and DeKalb counties. We provide county-level census data for areas without census tracts. The census tract boundary shape files come from the National Historical Geographic Information System (NHGIS).

1940 county population and housing layers:

The census data for this layer comes from the 1940 Decennial Census accessed via Social Explorer. The county boundary shapefiles come from NHGIS.

1955 aerial mosaic layer:

All aerials for this layer come from the USDA’s Aerial Photography Field Office (APFO). All aerial images in this layer were taken in 1955.

1956 census tract population and housing layers:

The census data for this layer was derived from the 1956 Atlanta Regional Commission (ARC) Population and Housing survey. Census tracts in 1956 only covered parts of Fulton and DeKalb counties. No county-level population and housing estimates exist for 1956. We provide 1950 county-level census data for areas without census tracts. We derived the black and white population estimates for the 1956 census tract by using the number of person per occupied dwelling unit and the number of dwelling units occupied by whites and non-whites tables. The census tract boundary shapefiles come from NHGIS.

1950 county population and housing layers:

The census data for this layer comes from the 1950 Decennial Census accessed via Social Explorer. The county boundary shapefiles come from NHGIS. 1968 aerial mosaic layer All aerials for this layer come from the United States Geological Survey’s (USGS) EarthExplorer. All aerial images in this layer were taken in 1968. The aerial images provided by EarthExplorer contained only partial coverage for Clayton, Fulton, and Gwinnett counties.

1968 population and housing layers:

The census data for this layer was derived from the 1968 ARC Population and Housing survey. The census tract boundary shapefiles come from NHGIS.

1972 aerial mosaic layer:

Nearly all aerials for this layer come from USDA’s APFO. However, USDA did not have full overage. Therefore, we filled in some small gaps by using a few USGS EarthExplorer images that were taken in 1974.

1972 population and housing layers:

The census data for this layer was derived from the 1972 ARC Population and Housing survey. The census tract boundary shapefiles come from NHGIS. 1981 aerial mosaic layer All aerials for this layer come from USDA’s APFO. All aerial images in this layer were taken in 1981.

1980 population and housing layers:

The census data for this layer comes from the 1980 Decennial Census accessed via Social Explorer. The census tract boundary shapefiles come from NHGIS.

1993 aerial mosaic layer:

All aerials for this layer come from USDA’s APFO. All aerial images in this layer were taken in 1993. 1993 population and housing layers The census data for this layer was derived from the 1993 ARC Population and Housing survey. The census tract boundary shapefiles come from NHGIS.

2005 satellite imagery mosaic layer:

All aerials for this layer come from USDA’s APFO. All images in this layer were taken in 2005. 2005 population and housing layers The census data for this layer comes from the 2005 to 2009 American Community Survey accessed via Social Explorer. The census tract boundary shapefiles come from NHGIS.

2013 satellite imagery mosaic layer:

All aerials for this layer come from USDA’s APFO. All images in this layer were taken in 2013. 2013 population and housing layers The census data for this layer comes from the 2009 to 2013 American Community Survey accessed via Social Explorer. The census tract boundary shapefiles come from NHGIS.