Figure 6

Coefficient changes and 95% CI of urban functional fragmentation characteristics on NO₂ variations based on four models. (a) Industrial ED; (b) Public ED; (c) Industrial LSI; (d) Public LSI; (e) Urban functional AI; (f) Urban functional NP. One unit of industrial ED is associated with − 0.0046 (95% CI − 0.0109 to 0.0017), − 0.0090 (95% CI − 0.0158 to − 0.0023), − 0.0105 (95% CI − 0.0157 to − 0.0053) and − 0.0168 (95% CI − 0.0213 to − 0.0122) NO₂ variations of UFB, UFD, UFCB and UFCD models, respectively. Per unit of public ED is linked with 0.0048 (95% CI − 0.0052 to 0.0148), 0.0024 (95% CI − 0.0083 to 0.0131), 0.0249 (95% CI 0.0166 to 0.0332) and 0.0232 (95% CI 0.0162 to 0.0303) NO₂ variations for four models. NO₂ variations of 0.0103 (95% CI − 0.0218 to 0.0424), − 0.0024 (95% CI − 0.0370 to 0.0321), 0.0360 (95% CI 0.0105 to 0.0616) and 0.0680 (95% CI 0.0454 to 0.0907) of four models are influenced by per unit of industrial LSI. For the public LSI characteristic, one unit of this is associated with 0.0405 (95% CI 0.0026 to 0.0784), − 0.0035 (95% CI − 0.0443 to 0.0373), − 0.0594 (95% CI − 0.0902 to − 0.0287) and − 0.0825 (95% CI − 0.1092 to − 0.0558) NO₂ variations of four models. Per unit of urban functional AI is associated with − 0.1047 (95% CI − 0.2110 to 0.0016), − 0.3165 (95% CI − 0.4308 to − 0.2022), − 0.1253 (95% CI − 0.2167 to − 0.0338) and − 0.1712 (95% CI − 0.2524 to − 0.0899) NO₂ variations of four models. One unit of urban functional NP is associated with − 0.0009 (95% CI − 0.0012 to − 0.0006), − 0.0011 (95% CI − 0.0014 to − 0.0008), − 0.0004 (95% CI − 0.0006 to − 0.0002) and − 0.0008 (95% CI − 0.0010 to − 0.0006) NO₂ variation of four models.