Abstract
<title>Abstract</title> <p>Air pollutant formation, stagnation, accumulation, and ventilation vary with urban spatial structure, yet emission-source-based research has insufficiently examined region-specific relationships between fine-scale urban form and pollution distribution. This gap is acute in large cities, where concentrated residential, business, and commercial functions complicate air-quality improvement. This study constructed a 100 m grid dataset for the Seoul metropolitan area to analyze intra-urban heterogeneity at the living-area level. Measurements of SO₂, CO, NO₂, O₃, PM10, and PM2.5 from 193 monitoring stations were used to calculate the Comprehensive Air-quality Index (CAI), while kriging estimated continuous pollution surfaces. Principal component analysis reduced 15 urban physical variables to four factors: urban enclosure, low-density buildings, high-density buildings, and development intensity. Geographically weighted regression identified region-specific determinants and showed markedly better fit than ordinary least squares, yielding a higher adjusted R² (0.9928 versus 0.0182) and lower root-mean-square error (0.247 versus 2.888). CAI values increased from northeastern Seoul (88–92) toward the southwest (96–104), while the four factors showed spatially varying effects across living areas. These findings underscore the need to extend emission-focused air-pollution analysis toward spatial diagnosis reflecting regional urban-form differences and provide an evidence-based, living-area framework for region-specific air-quality planning and policy implementation in high-density metropolitan contexts.</p>