Quantifying Urban Form: Compactness versus 'Sprawl'

Abstract

This paper develops a set of quantitative variables to characterise urban forms at the metropolitan level and, in particular, to distinguish compactness from 'sprawl'. It first reviews and analyses past research on the definitions of urban form, compactness and sprawl, and corresponding quantitative variables. Four quantitative variables are developed to measure four dimensions of urban form at the metropolitan level: metropolitan size, activity intensity, the degree that activities are evenly distributed, and the extent that high-density sub-areas are clustered. Through a series of simulation analyses, the global Moran coefficient, which characterises the fourth dimension, distinguishes compactness from sprawl. It is high, intermediate and close to zero for monocentric, polycentric and decentralised sprawling forms respectively. In addition, the more there is more local sprawl, composed of discontinuity and strip development, the lower is the Moran coefficient.

The impact of urban form on commuting in large Chinese cities

“…As significant clustering of high density areas in our case indicates the presence of concentrations of, for example, businesses, facilities and housing options, it can also considered as a proxy for urban compactness. Tsai (2005) showed in a simulation analysis that higher spatial autocorrelation coefficients correspond to more compact metropolitan areas. Since spatial clustering within a city can occur in one or more subcentres there is no direct relation with its degree of polycentricity.…”

Measuring the Complexity of Urban Form and Design

“…Beyond these qualitative formulations of complexity in urban form and design, how might it be measured and assessed? A stream of planning literature has considered quantitative measures of the urban form, but without explicitly engaging with complexity (e.g., Cervero and Kockelman 1997;Song and Knaap 2004;Tsai 2005;Clifton et al 2008;Ewing and Cervero 2010;Schwarz 2010;Song et al 2013b). Various complexity metrics at multiple scales, from metropolitan to neighborhood to building, are scattered throughout different bodies of literature.…”

Anatomía de la dispersión urbana en Barcelona

“…Se mide mediante el índice de Gini (Tsai, 2005). Otros indicadores similares utilizados en diferentes trabajos son el porcentaje de población y/o empleo que vive en zonas muy densas, la desviación típica de la densidad, el índice de disimilitud de Massey y Denton (Galster et al, 2001;Wolman et al, 2005), o los índices de Theil (Tsai, 2005) y Geary (Malpezzi & Guo, 2001).…”