Urban agglomeration: An evolving concept of an emerging phenomenon

TLDR

Urban agglomeration is a highly integrated spatial form where inter‑city relations shift from competition to a mix of competition and cooperation, making it a key driver of global economic development, yet consensus on its definition, delineation, and management remains elusive. The study seeks to establish a scientifically sound basis for the healthy and sustainable development of urban agglomerations. The authors reviewed 32,231 works over 120 years and performed fieldwork in China to identify four stages of spatial expansion and propose operable approaches and standards for defining agglomerations. The review delivers a theoretically supported and practically based definition of urban agglomeration and outlines four expansion stages with actionable criteria.

Abstract

Urban agglomeration is a highly developed spatial form of integrated cities. It occurs when the relationships among cities shift from mainly competition to both competition and cooperation. Cities are highly integrated within an urban agglomeration, which renders the agglomeration one of the most important carriers for global economic development. Studies on urban agglomerations have increased in recent decades. In the research community, a consensus with regard to what an urban agglomeration is, how an urban agglomeration is delineated in geographic space, what efficient models for urban agglomeration management are, etc. is not reached. The current review examines 32,231 urban agglomeration-related works from the past 120 years in an attempt to provide a theoretically supported and practically based definition of urban agglomeration. In addition, through this extensive literature review and fieldwork in China, the current research identifies the four stages of an urban agglomeration's spatial expansion and further proposes operable approaches and standards to define urban agglomerations. The study aims to provide a scientifically sound basis for the healthy and sustainable development of urban agglomerations.