September 26, 2010, 7:51 pm
Boundaries Without Boundaries
By Henry Woodbury
Almost by definition, map-based data draws a picture. Rarely is the picture so stark as Bill Rankin’s mapping of U.S. Census data on race and ethnicity to Chicago’s neighborhood boundaries.
Rankin draws attention not to the neighborhoods where his map confirms historical racial and ethnic boundaries, but to those whose gradient would otherwise go unnoticed:
My alternative is to use dot mapping to show three kinds of urban transitions. First, there are indeed areas where changes take place at very precise boundaries — such as between Lawndale and the Little Village, or Austin and Oak Park — and Chicago has more of these stark borders than most cities in the world. But transitions also take place through gradients and gaps as well, especially in the northwest and southeast. Using graphic conventions which allow these other possibilities to appear takes much more data, and requires more nuance in the way we talk about urban geography, but a cartography without boundaries can also make simplistic policy or urban design more difficult — in a good way.
Digital cartographer Eric Fischer takes Rankin’s approach and maps cities across the United States. Everywhere, ethnic and racial divisions present themselves, but there are dramatic differences in degree.
