Urban Green Space Per Capita for Sustainable and Equitable Urban Planning: A Systematic Review and Bibliometric Analysis

Urban Green Space Per Capita (UGSPC) is one of the oldest and most widely applied indicators in urban planning, providing a measure of green areas in relation to the population size. Despite its century-long application and decades of research, no global systematic review has previously synthesized how UGSPC has been applied, interpreted, and evolved across different contexts. This study aims to fill that gap by conducting the first comprehensive systematic review, following PRISMA guidelines, examining the usage, trends, and effectiveness of UGSPC in both developed and developing countries. Thematic analysis revealed that most studies were published in journals focused on sustainability and environmental science. The results show a surge in publications following the COVID-19 pandemic, reflecting a growing recognition of the importance of urban green spaces for public health and livability. Moreover, 67% of the studies were conducted in developing countries, while 30% of the publications were in developed countries. Higher UGSPC values are generally found in developed cities; however, this was not a rule. Time series studies showed a decline in UGSPC in some developed and developing countries, influenced by factors such as population density, urbanization stage, climate, and economic conditions. Although UGSPC is widely used, most municipalities typically develop their plans based on this measurement. 95% of the included research incorporated additional measurements, including accessibility, social equity, spatial patterns, ecological services, ecosystem benefits, and human health. This study suggests that UGSPC is still used as an indicator in urban planning and policy and integrating it with other indicators can serve as contemporary indicators to capture better equity, functionality, and sustainability in urban environments.