Land imperviousness reflects settlement growth and urban sprawl. Grounded on a comparative approach, a set of multidimensional statistical techniques were adopted here to quantify the evolution of land imperviousness from Copernicus High-Resolution Layers (HRLs) in a representative case study of Southern Europe (Athens, Greece). A two-way data matrix reporting the percent share of the surface land exposed to different sealing levels (101 classes ranging continuously from 0% to 100%) in the total municipal area was computed for two years (2006 and 2018) individually for 115 municipalities in metropolitan Athens. This matrix represented the information base needed to derive place-specific urban footprints and a comprehensive (global) profile of land imperviousness. Results of a Detrended Correspondence Analysis (DCA) delineated a metropolitan structure still organized along the density gradient, moving from dense settlements in central locations with dominant land classes sealed for more than 90% of their surface area to completely pervious land (0%) typical of rural locations. While the density gradient became less steep between 2006 and 2018, it continued to aliment a socioeconomic polarization in urban and rural districts with distinctive profiles of land imperviousness. Intermediate locations had more mixed imperviousness profiles as a result of urban sprawl. Differential profiles reflect place-specific urban footprints with distinctive land take rates.

A rank-size rule following Zipf’s law was tested along a complete urban–rural hierarchy in Greece using 2021 census data released at different administrative levels. Testing five econometric specifications (linear, quadratic, and cubic forms, together with refined logistic and Gompertz forms) on log-transformed population numbers, deviations from the rank-size rule were assumed as an indicator of economic concentration (considering settlements, population, and activities jointly) along the density gradient in Greece. This hypothesis was verified using progressively disaggregated population numbers at (i) regional units (n = 75), (ii) ‘Kallikratis’ municipalities (n = 333), (iii) ‘Kapodistrian’ municipalities (n = 1037), and (iv) local communities (n = 6126). Econometric results were stable across geographical levels and indicate a relatively poor fit of linear specifications, the classical formulation of Zipf’s law. Quadratic specifications displayed a good fit for all territorial levels outperforming cubic specifications. Gompertz specifications outperformed logistic specifications under aggregate partitions (e.g., regional units and ‘Kallikratis’ municipalities). Quadratic specifications outperformed both logistic and Gompertz specifications under disaggregated levels of investigation (‘Kapodistrian’ municipalities and local communities). Altogether, these findings indicate the persistence of non-linear rank-size relationships estimated over a cross-section of population data at progressively detailed observational units. Such evidence enriches the recent literature on Zipf’s law, demonstrating the inherent complexity of rank-size rules tested on real data along the whole density gradient in a given country.

To delineate new directions of urban development in a context of demographic shrinkage in Southern Europe, the present study illustrates a comparative analysis of the demographic balance in metropolitan Athens, Greece (1956–2021). The analysis delineates short-term and long-term dynamics of the natural population balance, considering the impact of the Great Recession and COVID-19 pandemic, and assuming a contemporary increase in gross mortality rates and a marked fertility reduction associated with birth postponement. To address such objectives, we have compared the natural growth of population (the ratio of the total number of births to deaths) at ten year intervals (1956, 1960, 1970, 1980, 1990, 2000, 2009, 2019, 2020, 2021) in 115 municipalities of metropolitan Athens, controlling for the local context. The empirical results of descriptive statistics, spatial analysis, correlation statistics, non-parametric inference, and exploratory multivariate techniques outline the indirect impact of COVID-19 on population dynamics, being in some ways additive to the already observed effects of the Great Recession, reinforcing demographic shrinkage in specific local contexts. The COVID-19 pandemic and the Great Crisis likely accelerated the typical outcomes (population aging and low fertility) of the second demographic transition in Greece. These dynamics are associated with more volatile (and possibly reduced) immigration flows and with enhanced emigration, fueling urban shrinkage and a progressive economic decline of metropolitan regions, as our evidence suggests for Athens. Additional research should ascertain the aggregate, indirect role of pandemics in population dynamics as a proxy of urban and regional decline in European regions exposed to long-term aging.