Boundary Issues: The 2016 Atlas of Urban Expansion Indicates Global Dedensification

John Wihbey
Northeastern University

This article was originally published in the October 2016 issue of Land Lines, the quarterly magazine of the Lincoln Institute of Land Policy.

Cities around the world are consuming land at a rate that exceeds population growth, according to the 2016 Atlas of Urban Expansion—a precise analysis of 200 global urban growth boundaries drawn from satellite images, population figures, and other data. Produced through a partnership among the United Nations Programme for Human Settlements, the New York University Urban Expansion Program, and the Lincoln Institute of Land Policy, the study parses the drivers and effects of sprawl and creates the basis for a science of cities. This article examines some of the critical findings of the Atlas of Urban Expansion, such as a general trend of falling density across the world’s cities, as well as the identification of a variety of aerial visual signatures of unplanned settlements. Future data collection challenges and implications for land use policy are discussed.