Automated delimitation of urban areas comprising small-sized towns – Comparison of two methodologies applied to mainland Portugal

Abstract

At European level, the different methodologies used for the classification of urban areas rely on the spatial allocation of population to 1 km² grid cells, failing therefore to identify small-sized settlements that play an important role in urban systems mostly composed by small towns, such as the Portuguese. This paper reports the development of alternative methodologies which overcome the problem stated, successfully enabling the automated recognition and delimitation of small-sized urban settlements – the prime goal of this work.

Two alternative methodologies (A and B) were developed and later compared. The settlements identified by A are clusters of census tracts, previously classified using an urban–rural typology proposed by the authors. In B an adaptation of the Urban Morphological Zones methodology published by the European Environment Agency was used, whereby settlements are clusters of specific Land Use/Land Cover classes combined with the urbanised areas defined by Municipal Master Plans.