URBAN SPRAWL METRICS: AN ANALYSIS OF GLOBAL URBAN EXPANSION USING GIS

Abstract

We define and present a comprehensive set of metrics for five dynamic attributes of urban spatial structure commonly associated with ‘sprawl’: (a) the extension of the area of cities beyond the walkable range and the emergence of ‘endless ’ cities; (b) the persistent decline in urban densities and the increasing consumption of land resources by urban dwellers; (c) ongoing suburbanization and the decreasing share of the population living and working in metropolitan centers; (d) the diminished contiguity of the built-up areas of cities and the increased fragmentation of open space in and around them; and (e) the increased compactness of cities as the areas between their fingerlike extensions are filled in. We also introduce several metrics for key manifestations of sprawl. We present these metrics as well as actual calculations of these metrics for two cities: Bangkok and Minneapolis. A forthcoming paper will present similar results for a global sample of 120 cities.