Mapping the Spatial Conditions of Polycentric Urban Development in Europe: An Open‐source Software Tool

Abstract

Urban polycentricity has become a key concept in urban and regional studies and is increasingly adopted as an organizational framework for conducting empirical research. Within this literature, polycentric urban regions are commonly defined as territories that have multiple, proximately located (sub)centers and are characterized by balanced urban development. However, analytical‐operational frameworks to identify and classify PURs are often ad hoc efforts to answer a specific research question and underlying work is often shelved rather than shared and/or made accessible. As a result, challenges associated with generalizability, reproducibility, and replicability clearly loom large in the urban polycentricity literature. Against this backdrop, this article describes the discrepancy between a rich debate on polycentricity and the paucity of tools enabling the disambiguation and reproducibility of results claimed by various authors around this polysemic concept. We present an online and open tool—PURban—that brings together the major analytical‐operational frameworks and data sets in urban polycentricity research and allows parametrizing key operational choices. To illustrate the tool, we demonstrate how it facilitates the identification, mapping and analysis of degrees of morphological polycentricity in European urban systems. We conclude by reflecting on how this tool can act as a catalyst for future research on urban polycentricity.

The productivity effects of polycentricity: A systematic analysis of urban regions in Europe

“…PURban, presented in Caset et al (2022), defines the building blocks (or “cities”) of PURs on the basis of the Global Human Settlement Layer (GHSL) Urban Centre Database (hereafter GHS‐UCDB, see Florczyk, Corbane, Schiavina, et al, 2019). This database is based on the “degree of urbanization” concept (Dijkstra & Poelman, 2014), which devises a consistent definition of urban areas to create a global database of “urban centres” (UCs).…”

“…Subsection 2.2 elaborated on the thorny issue of different analytical‐operational frameworks possibly leading to different outcomes. In terms of the measurement of urban polycentricity, this paper addresses this issue by building on recent contributions in the PUR literature (Caset et al, 2022; Derudder et al, 2021) that have culminated in the development of an open‐source software tool called PURban. This tool brings together the major analytical‐operational frameworks and datasets in urban polycentricity research and identifies, maps, and analyses degrees of morphological polycentricity in European urban systems.…”

“…Subsection 2.2 elaborated on the thorny issue of different analytical-operational frameworks possibly leading to different outcomes. In terms of the measurement of urban polycentricity, this paper addresses this issue by building on recent contributions in the PUR literature (Caset et al, 2022;Derudder et al, 2021) imum spacing between urban centres or a minimum population potential). Additionally, our analysis is not confined to administrative urban and regional/national delineations.…”

The Legitimacy of new Regionalism in the European Integration Process

“…It calculates the dominance of the prime city, so it gives little detail about the size of the other cities or towns and, if the distribution is relevant, it can't be used on its own (Nikolopoulos, Gkouzos and Papadaskalopoulos, 2018;Sat, 2018bSat, , 2018aŽivanović et al, 2019). Still on the morphological side, the Herfindahl index is also used to measure polycentricity (Meijers, Hoogerbrugge and Cardoso, 2018;Caset et al, 2022).…”