A systematic review of morphological transformation of urban open spaces: drivers, trends, and methods

Abstract

Ongoing urbanization has led to the continuous expansion of built-up areas; as a result, open space is under great threat. Despite the wealth of studies conducted on open spaces, there is still a further need to further investigate the morphology of open space, particularly in an effort to understand the trends and drivers of open space morphological transformation that remain under-researched. Besides, although the previous literature has highlighted several factors influencing urban space morphology, it remains unclear how those key drivers interact. In this article, the PRISMA methodology was used to conduct a systematic literature review, screening and selecting articles from three primary databases (Web of Science, Elsevier, and Scopus). In total, 47 journal articles covering the years 2000 to 2022 were selected for the final review to identify key factors that influence open space morphology, including natural geographical factors, socioeconomic factors, and government policy factors. The results indicate that, as cities developed, the size of green spaces decreased, their structure fragmented, and their distribution became progressively less connected. Meanwhile, socioeconomic determinants played a greater role in influencing changes in green spaces than natural geographical factors and policy management factors. In addition, carrying out the present study confirmed that Landsat remote-sensing data with landscape metrics is a powerful research method for studying green space change. A research framework is offered in this paper to illustrate an understanding of which factors influence the dynamics of green spaces, identify the interaction mechanisms, and provide an optimization strategy of urban open space for urban planners or policymakers.