Spatial Structure and Inter-Urban Relations: A Scientometric Mapping Approach

Over the last two decades, the focus of studies on the spatial organization of urban systems has shifted noticeably from classical theories such as “the central place theory” to utilizing novel theories based on the network essence of intercity relations, such as “the central flow theory”. This field of urban research, which has emerged under the term “external urban relations”, has developed through integrating contributions from many disciplines. However, different methodological traditions and interdisciplinary contexts in which the research is conducted are leading to ambiguity in how we understand and measure intercity relations. This study systematically reviews and analyzes the body of this new literature. It does so by innovatively employing a scientometric mapping approach, which is a combination of bibliometric and citation network analysis methods. This review is based on a publication set of 145 papers published on the subject since 1995. The number of publications covered by the Web of Science (WoS) shows a significant increase in the most recent years. The current study identifies 20 papers as playing a pivotal role in the evolution of the literature on urban external relations. Furthermore, the results revealed five conceptualizations before the 1990s at the classical theories era, along with two renowned conceptualizations during the 1990s (the transition decade), which have had the most impact on changes in the metamorphosis of theoretical fundamentals. The present developments are influenced by a wide range of various concepts, methods, and empirical approaches. Two different subfields (schools) of thought known as “world/global cities”, and “polycentricity” are identified by systemically integrating traditional top-down and bottom-up review methods. Their different aspects were also discussed.