Methodological Exploration to Integrate Urban Green Infrastructure with Spatial Planning and Decision-making Process: A Literature Review

Abstract

In recent years, Urban Green Infrastructure (UGI) has been recognized as a cost-effective nature-based environmental solution. It combines the benefits of the existing built environment with those needed to improve the quality of residence and ecosystem health (Osmond and Wilkinson, 2021). Although the contribution of UGI has been widely discussed, the disconnect between theory, policy, and management has resulted in UGI being relegated to a secondary position or neglected in urban planning decisions. However, there is a research gap in the contemporary planning literature on how UGI enters the planning and decision-making process. Therefore, this study aims to identify the current barriers to UGI's entry into the planning decisions and the solutions to these resistances. The study firstly summarizes the literature on the UGI systematic review to clarify the direction of the current research issues. The present problems of UGI mentioned in the issue are further classified into two categories: clarified and yet to be clarified by reviewing the literature on their corresponding methodologies. Finally, the methodologies that are missing and need to be strengthened for the future development of UGI are proposed. This research suggests that ambiguous definitions and design principles (Monteiro, Ferreira and Antunes, 2020) and a lack of interaction with other disciplines (Hansen et al., 2019) act as barriers for UGI to enter the planning decision-making process. In particular, the economic and socio-benefits of UGI have been underestimated due to the lack of clarity. The existing research on the economic-social aspects of UGI focuses on five themes: 1) the spatial justice of UGI; 2) the indirect impacts of UGI on housing prices and investment; 3) UGI performance and cost-benefit analyses; 4) assessment of the economic and social values of UGI ecosystem services; and 5) the bio-economic value provided by UGI. The results show that the existing economic benefits of UGIs are assessed by quantifying the ecological benefits of UGIs (e.g. carbon sequestration, air purification, quality of the residential environment, etc.) into specific monetary values, and by rating extant UGI projects using SWAT analysis and weighted scores. Social benefits were assessed in terms of the number of people positively impacted by UGIs and in terms of UGI spatial justice. The complexity of socioeconomics increases the need to evaluate the economic and social benefits of UGIs. This study will provide a research direction for incorporating UGIs into urban planning decisions.