Researchers take step back to see urban sprawl

Researchers take step back to see urban sprawl


Canada, 2 May 2006 – Using satellite and aerial photography, several academic researchers including two from the University of Toronto have created the most comprehensive picture of urban sprawl in the United States to date. Until now, most debate on the subject of sprawl has been speculative, the researchers argue.

”If you wanted to actually look at land use, nobody has the data,” contends Matthew Turner, an assistant professor of economics at the University of Toronto and one of the study’s authors. With three other researchers, Turner merged high-altitude photos taken in 1976 with satellite images from 1992 the most recent ones available to create a grid of 8.7 billion 30-metre-by-30-metre plots of the U.S.

Their research, titled Causes of Sprawl: A Portrait from Space, appears in the May issue of The Quarterly Journal of Economics. The academics applied their research to the U.S. rather than Canada because similar data isn’t available publicly north of the border. While
the Americans have organized their Geographic Information System data and made it freely available on the web, it would cost Canadians $50 million to carry out the same research, Turner said.

”We’d have to buy the satellite data and hire all the geographers to do all the processing of the data before we got to it.” Turner first began thinking about the problem several years ago while staying in a hotel at the edge of Little Rock, Ark. In order to get to a
nearby restaurant, the academic had to cross two parking lots and six lanes of traffic.

The researchers found Pittsburgh and Atlanta have sprawled the most, while Miami, San Francisco and Los Angeles among major American cities have controlled their growth. In general, development in the U.S. increased by 48 per cent between 1976 to 1992. A city’s climate, topography and access to groundwater account for up to 25 per cent of the variation in a region’s sprawl.