Characterization of tropospheric ozone pollution, random forest trend prediction and analysis of influencing factors in South-western Europe

Environmental Sciences Europe

Table 3 Path coefficient analysis between tropospheric ozone and human influencing factors

Item	Direct path coefficient	Indirect connection diameter coefficients
Item	Direct path coefficient	X₁−Y	X₂−Y	X₃−Y	X₄−Y	X₅−Y	X₆−Y	X₇−Y
Population, total (X₁)	0.3868	–	−0.3027	−0.1641	−0.5712	0.6490	−0.0340	0.0197
Population density (X₂)	1.1433	−0.0983	–	0.0040	−0.3903	−0.7191	0.1348	−0.0082
PM_2.5 air pollution (X₃)	− 0.4496	0.1388	−0.0100	–	0.4179	−0.3456	0.0086	0.0006
Total greenhouse gas emissions (kt of CO₂ equivalent) (X₄)	1.2827	−0.1685	−0.3365	−0.1525	–	−0.3805	−0.0714	−0.0063
Forest area (% of land area) (X₅)	1.4749	0.1765	−0.5767	0.1151	−0.3508	–	−0.2049	0.0196
Urban population (X₆)	0.2878	−0.0454	0.5523	−0.0131	−0.3181	−0.9621	–	−0.0204
Other manufacturing (% of value added in manufacturing) (X₇)	0.0442	0.1767	−0.2002	−0.0061	−0.1874	0.6273	−0.1373	–