The vague boundaries of urban-metropolitan space in Spain

Abstract

The paper, stressing the strategic significance of urban and metropolitan spaces and
highlighting the difficulties for its definition and delimitation, developed a method to measure
the rural-urban gradient in Spain, based on both its 8,116 municipalities and its 61,578 entities
of population. Once established, the urban system is classified on the basis of these entities
of population, and the structure presented by urban-metropolitan areas is analyzed using the
kernel or focal lengths method. The article defends the hypothesis that the rural-urban gradient
concept, analyzed from the fuzzy logic, is more appropriate than the urban - non-urban absolute
categories, more specific in Boolean logic. This change on the theoretical and conceptual
perspective implies a change in the methodological perspective. It raises, as an alternative to
cartographic models based on binary criteria, more advanced methods such as the logic of the
blurry sets. These methodologies allow to empirically verify the hypothesis that the rural and
urban are not currently elements of a polarized, dual and binary model, but elements of the
same system in which the idea of continuum or rural-urban gradient reflects the territorial
reality better than any other concept. The paper concludes with an analysis of land uses for two
case studies: Madrid and Barcelona.