Assessing the Impact of Urban Green Infrastructure on Air Quality and Heat Island Mitigation: A Comparative Study of High-Density Cities

Abstract

Urban Green Infrastructure (UGI) has emerged as a sustainable and nature-based solution to address environmental challenges in densely populated cities. This study investigates the role of various green infrastructure components—such as green roofs, urban forests, vertical gardens, and green corridors—in improving air quality and mitigating the Urban Heat Island (UHI) effect across selected high-density cities. Using a comparative approach, the research combines satellite imagery analysis, ground-based air quality monitoring data, and surface temperature measurements to evaluate the environmental performance of UGI systems in cities with varying geographic and climatic conditions. The results indicate that cities with well-integrated green infrastructure exhibit notably lower concentrations of particulate matter (PM2.5 and PM10) and nitrogen dioxide (NO₂), along with significant reductions in surface and ambient temperatures. The study also highlights differences in UGI effectiveness based on local governance policies, design strategies, and public participation. The findings underscore the potential of UGI as a multifunctional tool for urban sustainability and advocate for its integration into long-term urban planning and climate adaptation frameworks.