Investigating Metropolitan Hierarchies through a Spatially Explicit (Local) Approach

Abstract

Assuming a non-neutral impact of space, an explicit assessment of metropolitan hierarchies based on local regression models produces a refined description of population settlement patterns and processes over time. We used Geographically Weighted Regressions (GWR) to provide an enriched interpretation of the density gradient in Greece, estimating a spatially explicit rank–size relationship inspired by Zipf’s law. The empirical results of the GWR models quantified the adherence of real data (municipal population density as a predictor of metropolitan hierarchy) to the operational assumptions of the rank–size relationship. Local deviations from its prediction were explained considering the peculiarity of the metropolitan cycle (1961–2011) in the country. Although preliminary and exploratory, these findings decomposed representative population dynamics in two stages of the cycle (namely urbanization, 1961–1991, and suburbanization, 1991–2011). Being in line with earlier studies, this timing allowed a geographical interpretation of the evolution of a particularly complex metropolitan system with intense (urban) primacy and a weak level of rural development over a sufficiently long time interval. Introducing a spatially explicit estimation of the rank–size relationship at detailed territorial resolutions provided an original contribution to regional science, covering broad geographical scales.

Envisaging the Intrinsic Departure from Zipf’s Law as an Indicator of Economic Concentration along Urban–Rural Gradients

“…In the case of Greece, heterogeneity in urban areas possibly derives from the evident differences in urban size among the ten largest cities in the country, with two leaders (Athens and Thessaloniki) and some laggers with a completely different (lower) economic size and governance power [70]. Heterogeneity in rural areas is lower because of the intrinsic conditions of remoteness and economic backwardness typical of inland locations with an economic system dominated by low-value-added activities such as traditional farming and unspecialized forestry [71]. Heterogeneity in the intermediate locations-e.g., agricultural districts specialized in tourism and intensive crop productions frequently linked with urban markets-may explain, at least in part, the differential rank-size rule compared to strictly urban and strictly rural locations [9].…”

“…The population data used here are the most updated in the country since administrative registers releasing annual demographic estimates of the total population provided suitable and comparable data only at NUTS-0, 1, 2, and 3 levels. This means that population data at more granular domains (such as NUTS-5, LAU-1, and LAU-2 units) were (and still are) available only from population censuses held every ten years in Greece [71]. Despite having slight differences in the administrative structure of the country since 1991, the spatial distribution of the population was rather stable over time in the last three decades, as demonstrated in the corresponding population census [72].…”