One dot, one person: population density maps for Virginia cities
The dot density map of U.S., Canadian, and Mexico census data by MIT’s Media Lab got a lot of attention…so we decided to give it a try ourselves, taking a deeper look into census data for Virginia’s major urban centers and smaller cities. All of the dots on the following maps represent one person, as enumerated by the 2010 Census, with a little bit of a twist. Rather than giving everyone a black dot, as MIT’s Media Lab did, we added another layer of data by assigning color dots based on race and ethnicity. The results are quite illuminating…
Take the City of Charlottesville as an example:
The great thing about dot density maps is that they elegantly convey a lot of data in a small space. Total population, population density, geographic distribution, and race/ethnicity are displayed in a single visual. Also, by incorporating the racial and ethnic data, the extent and degree of residential segregation manifests itself. These maps still work for even the most densely populated areas…
Fairfax, the Beltway, and Manassas:
Norfolk, Portsmouth, Newport News, and Hampton:
However, like the Charlottesville example, some of most interesting maps are for Virginia’s smaller cities and towns.
Winchester City:
Despite their utility and beauty, these maps have their limitations. They are bounded by the highest resolution possible with census data, namely population data by Census Block, the smallest unit of census geography (roughly equivalent to a city block in a urban area). The dots are randomly placed within Census Blocks so sometimes may not represent actual residences for some larger area and less-populated Census Blocks.
Note: The racial categories for White, Black, Asian, and Other are all non-Hispanic. Hispanic dots represent a person of any race, but are usually categorized as Hispanic White or Hispanic Other.