Towards a simpler characterization of urban sprawl across urban areas in Europe.

Urban sprawl is a concept commonly used to describe the physical expansion of urban areas. It is traditionally associated with lower residential density, poorer connectivity and higher energy costs for heating and transport. From the period of 1980 to 2000, the extent of built-up area in Europe has increased at a rate 3 times higher than that of population increase and urban sprawl is now recognized as a major challenge. However, in order for policies to address this issue, it is essential to be able to clearly identify and quantify sprawl. While the concept of sprawl is relatively simple, there is no internationally agreed definition of what constitutes sprawl nor is there an agreed methodology on how to measure and define it in a quantitative manner. This paper describes an attempt at characterizing urban sprawl across urban areas at a pan European scale, by presenting a new indicator, the Averaged Concentric Weighted Urban Proliferation (ACWUP) index. This index is calculated by aggregating the “sprawl profile” of urban areas, derived from an adapted version of the Weighted Urban Proliferation index applied to EU28-wide 100m resolution gridded population and land-use data. In comparison to other approaches, the proposed indicator (1) is data cheap and quick to produce and (2) provides a unique synthetic value characterizing the sprawl status of individual cities. We believe this indicator and its associated sprawl profile could be used to as a first approximation to characterize and compare urban sprawl across cities.JRC.B.3-Territorial Developmen