A relative measure of urban sprawl for Italian municipalities using satellite Light Images

At the local level, the lower the urban density, the higher the per-capita length of collector roads and the area covered by buildings and infrastructures. It follows that the lower the urban density, the higher the municipal luminosity. For this reason, night-time light is often used in order to evaluate the degree of urbanization and urban sprawl in a specific territory by means of specific indicators. However, to the best of our knowledge, these indicators are based on an absolute evaluation of the urban sprawl, without taking into account the peculiar economic and demographic characteristics of the urban centres. In this paper we propose a regression-based measure of urban sprawl “relative” to the economic activity and to other socio-demographic characteristics of municipalities. We apply this methodology to the Italian context, considering all Italian municipalities inside the 15 ordinary regions over the period 2004- 2012. The measure we propose, thus, takes into account also a time element.