Refining green space renewal for PM10 mitigation across heterogeneous built environments

Urban green space renewal is essential for improving air quality in rapidly urbanizing areas. Understanding the interactive effects of building-green space on PM 10 is key to developing effective mitigation strategies. This study compared the seasonal distribution patterns of PM 10 , investigated the interactive effects of building-green space configurations on PM 10 , and identified the nonlinear response relationships and threshold effects between urban spatial patterns and PM 10 concentrations. The results indicated that floor area ratio (FAR) dominated PM 10 regulation in spring and summer. When 0.8 < FAR <1.6, combinations with moderate-to-low NDVI (0.25–0.5), high vegetation surface area (VSA: 400,000–780,000 m 2 ), and high building-vegetation volume ratio (BVVR: 7.5–12.5) significantly reduced PM 10 concentrations. In contrast, the building shape coefficient (BSC) dominated PM 10 regulation in autumn and winter. When BSC approached or exceeded 0.2, its interactions with lower NDVI and higher VSA consistently produced lower SHAP values, and nonlinear fitting confirmed that combinations with NDVI <0.15 or 0.3 < NDVI<0.48 and 400,000 < VSA < 780,000 m 2 were effective in mitigating PM 10 . The findings highlight threshold effects of green space under heterogeneous built environments and provide a scientific basis for green space renewal to enhance PM 10 mitigation.