Assessing the Connectivity of Urban Green Spaces for Enhanced Environmental Justice and Ecosystem Service Flow: A Study of Tehran Using Graph Theory and Least-Cost Analysis

This research aims to analyze the relationship between environmental justice and urban green space connectivity in Tehran, Iran. The evaluation of green space connectivity in this study is conducted through two distinct cost layers: one aimed at enhancing existing connections and another focused on establishing new green spaces. Key factors influencing connectivity, extracted from the relevant literature, were identified to facilitate this analysis. Employing graph theory and least-cost analysis, the results determined critical resistance factors, current connectivity and cost status, the varying degrees to which different districts benefit from green space ecosystem services, and the most effective routes for establishing green corridors. Research findings highlight significant disparities in access to these services, particularly in the underserved central districts of Tehran. Moreover, spatial analysis reveals a higher potential for enhancing east–west ecosystem service corridors due to the higher density of green hubs and lower costs in this orientation, while north–south connectivity faces more challenges. By exploring land use/land cover, and physical and socio-economic factors affecting urban green space connectivity, this study provides urban and environmental planners with a novel methodology and comprehensive insights for effective decision making, resource allocation, and land use planning.