HIGH RESOLUTION DEMOGRAPHIC GRIDS
We developed three types of high resolution grids: population grids, subpopulation (or race-specific) grids, diversity/dominant race classification grids.
High resolution grids have been calculated from census blocks using the dasymetric modeling technique. The spatial resolution of these grids is 30m.
DATA FORMAT: GeoTiff
DATA AVAILABILITY: each county and 363 metropolitan areas for 1990, 2000, and 2010 as multi-year comparable datasets (called “myc”).
For 2010 we also made available additional datasets, that used more detailed ancillary information, but cannot be used for change analysis.
Population and racial diversity/dominant race grids for the conterminous U.S are available via SocScape – GeoWeb application. GeoWeb application allows for exploring U.S data down to street level and download data for the area up to 100,000 sq. km.
Data for the counties and metropolitan areas are organized as a zip archive with population, race-specific, and diversity/dominant race grids.
- A. Dmowska, T. F. Stepinski, P. Netzel (2017) Comprehensive framework for visualizing and analyzing spatio-temporal dynamics of racial diversity in the entire United States, PLoS ONE 12 (3): e0174993. paper (open access)
- A. Dmowska and T. F. Stepinski (2017) A high resolution population grid for the conterminous United States: The 2010 edition. Computers, Environment and Urban Systems 61, pp. 13-23. paper, preprint
RACIAL DIVERSITY CHANGE DATASET
The racial diversity change dataset shows temporal changes in racial diversity/dominant race in a single map. Changed areas are shown in stripes with the color of narrower stripes indicating the earlier year (f.e 1990) and broader stripes indicating the later year (f.e. 2000). Unchanged areas are shown in original color assign to this class in racial diversity maps. A detailed description of the racial diversity change dataset is here.
DATA FORMAT: ESRI Shapefile
DATA AVAILABILITY: 351 urban areas within metropolitan areas for 1990-2000, 2000-2010, and 1990-2010 comparison.
RACIAL DOT MAPS
Racial dot maps show the spatial distribution of a population density and the full racial composition in a single map. In a dot map, each dot represents one person and it's colored by their race. This dataset was calculated using 2010 high resolution grids (instead of census units), and each dot is randomly placed within a 30x30m grid cell. Each dot has assigned one of 7 racial/ethnicity categories: (non-Hispanic) white, black, Asians, Pacific Islanders, Native Americans, others, and Hispanic.
DATA FORMAT: ESRI Shapefile.
Race categories are stored in the race_cat column in the attribute table, while race_id contains numeric identification for the race.
DATA AVAILABILITY: each county in the conterminous U.S.; 2010 year.
Data are organized as a zip archive for each state in the conterminous U.S. Each zip archive contains racial dot maps for the counties in this state.
The dot map for other years can be calculated using the R script and high resolution grids available here.
- A. Dmowska and T. F. Stepinski (2019) Racial Dot Maps Based on Dasymetrically Modeled Gridded Population Data, Soc. Sci. 8(5), 157 paper (open access)
RACIAL COMPOSITION IN THE US CITIES USING HISTORICAL CENSUS TRACTS (1910-2010)
Using available census tract data provided by the NHGIS project, we unified race categories and calculated race dominant/diversity classes for 63 metropolitan areas. Such data can be used to illustrate changes in the racial composition in 1910-2010.
DATA FORMAT: ESRI Shapefile
The attribute table contains the following information: code and name of county, state, MSA and tract information, the total number of population and the number of subpopulations by given race, percent of a given race, and a class from dominant race/diversity classification. The location information is based on the 2010 US Decennial Census to assure comparability between years. The race-specific information is the unified race classification.
DATA AVAILABILITY: metropolitan areas (MSA) for which at least data from 1950 is available (list of MSA).
Data are organized as a zip archive for a metropolitan area. Each zip archive contains an ESRI shapefile for available years and a QGIS legend file to map racial diversity classification.
- A. Dmowska, T. F. Stepinski (2020) Mapping changes in racial composition in the United States 1910-2010 using US census tract historical data (paper submitted to Historical Methods: A Journal of Quantitative and Interdisciplinary History).