America's Growing Urban Footprint
Not only are more Americans living in urban areas, but those urban areas are getting bigger.
According to new figures from the U.S. Census Bureau, more than 80 percent of the U.S. population lives in urban areas – areas that range wildly in population and density, as we recently reported. And with this latest count of urban dwellers, the Census Bureau has also released revised measurements of just how big the country's urban areas are geographically. With the rise in urban population, there has also been a rise in the sheer size of many cities and urban areas.
Atlanta saw the largest absolute increase in its urban area between 2000 and 2010, growing from 1,962 square miles to 2,645, an increase of nearly 683 square miles.
"The suburbs are just growing outward," says Kevin Hawley, a geographer at the Census Bureau. "That seems to be the case in most of the larger areas."
These growing urban areas aren't just cities extending their borders, according to Hawley, but rather clusters of urban development on the fringes of cities that are growing towards each other. As two areas spread out and get closer together, the space in between "gets sort of swallowed as growth between the two areas happens," Hawley says.
And though Atlanta is somewhat of an outlier in terms of its huge expansion, many other cities saw large increases in their urban areas. There were 29 that saw increases of 100 square miles or more. And 76 saw increases of 50 square miles or more.
This chart shows the 10 cities with the largest urban land area increase, by square miles, between 2000 and 2010.
Four of the top ten growing cities, it's worth underlining, are in Texas. This is a state that experienced a 20 percent population growth rate between 2000 and 2010, and will be gaining an additional four congressional representatives through reapportionment.
The largest increase in urban land for a Texas city was in Dallas, which grew by about 372 square miles. Rosanne Ortega, executive director of the Greater Dallas Planning Council, says the state's relatively resilient economy is behind the population growth that's been fueling this urban expansion.
"North Texas especially hasn’t experienced quite the dramatic downturn that any of the other major metropolitan areas like Chicago or Detroit have experienced. So a lot of our jobs, even in construction, have been maintained," Ortega says.
It's not just big cities that are seeing this sort of edgewise expansion. Small and mid-sized cities are also growing. In fact, the cities that saw the largest growth rate between 2000 and 2010 are mainly in the 60,000 to 200,000 range.
The next chart shows the 10 cities that saw the largest increase in urban land area by percentage.
As I noted in an earlier article on the new urban numbers from the Census, there are officially two types of urban areas: “urbanized areas” of 50,000 or more people and “urban clusters” of between 2,500 and 50,000 people. Hawley says that the 2010 census was only the second census to track urban clusters, making historical comparison impossible. But for the larger urbanized areas, the census has kept track of changes in urban area. The 1990 figures are deep inside this document [PDF].
This last chart shows how U.S. urban land area has grown since 1990 in the 10 biggest gainers of 2010.
We won't be able to do any sort of comparable analysis of the smaller urban clusters (those in the 2,500 to 50,000 population range) until the numbers come back from the 2020 Census. But when those numbers do come out, they're likely to show similarly big increases in the amount of urban land each of these areas encompasses. Between 2000 and 2010, almost every urban area in the country expanded physically. Of the roughly 3,500 urban areas in the U.S., only about 50 shrank in size over the last decade. As the urban population of the country grows, the physical footprint of urbanity can be expected to grow right along with it.
Top image: Downtown Las Colinas, Texas, a suburb of Dallas. (Kushal Bose/Shutterstock)