Study reveals hidden mechanisms behind urban sprawl
Cities are expanding all over the world, but the mechanisms governing this growth remain poorly understood.
In a study published in Physical Review Letters, Marc Barthelemy, from the Institute of Theoretical Physics (CEA & CNRS) and the Center for Social Analysis and Mathematics (CNRS/EHESS), together with his colleagues from the University of Trento and the University of Barcelona, addressed this issue.
Using satellite data to track the evolution of 19 cities between 1985 and 2015 and applying tools from physics—usually used to study surface growth or crystal formation—these researchers discovered that urban growth is not random.
On the contrary, it follows clear patterns: cities tend to develop in uneven, branched forms, and there is a constant relationship between the built-up area and the population living there.
These results are important because urban sprawl influences all aspects of urban life, from transportation and housing to the environment.
Understanding the hidden structure of city expansion can help urban planners, scientists, and policymakers make better decisions for the future of urban growth—and provides the empirical basis needed to build reliable models of city development.
More information:
Ulysse Marquis et al, Universal Roughness and the Dynamics of Urban Expansion, Physical Review Letters (2025). DOI: 10.1103/rlkq-t36n
Provided by The Institute of Theoretical Physics (IPhT)
