Trend watch! Supercities will be all the rage in the 21st century, as fully 2/3 of the world’s population concentrates in urban regions. This centuries-long migration represents the culmination of a process of industrialization stretching back to the early 1800s, with all of its attendant social and environmental consequences.
I’ve got a handful of links that take a data-driven driven look at cities. First up, what do large cities and elephants have in common? Both appear to be organized according to underlying mathematical principles that make them more efficient than their smaller cousins. On a pound-for-pound basis, an elephant uses less resources than a mouse. To be precise:
> The relevant law of metabolism, called Kleiber’s law, states that the metabolic needs of a mammal grow in proportion to its body weight raised to the 0.74 power.
Cities behave much the same way:
> For instance, if one city is 10 times as populous as another one, does it need 10 times as many gas stations? No. Bigger cities have more gas stations than smaller ones (of course), but not nearly in direct proportion to their size. The number of gas stations grows only in proportion to the 0.77 power of population.
The gas station example is a trivial application of what appears to be a deep relationship. Cities, with their branching patterns of pipes, sewers, streets, and wires, appear to become more efficient in size in just the same way living organisms do, which is one of the reasons that increasing urbanization is on balance good for the planet.
Not that we should take the greater efficiency of cities for granted. Humans control their built environments in ways that have dramatic consequences. In a simple but revealing demonstration of the different forms cities can take, Neil Freeman has traced a series of subways systems, all to the same scale. Here’s Tokyo juxtaposed with the San Francisco bay area:
Check out the entire series. How does your city compare?
Finally, Richard Saul Wurzman, founder of the TED conferences and renowned information architect, has launched 192021.org, a five-year project to collect and share information about the rising supercities, defined as urban areas with populations of more than 20 million. The site right now is just an overview of the project, but it’s worth spending the five minutes it takes to go through the presentation. The changing map showing the development of cities over the past 1,000 years alone is worth the price of admission. (via The City Fix)