Fig 1.
Study area showing power stations, major roads and municipality-level population distribution of South Africa.
Fig 2.
The spatial distributions of socio-environmental predictors and NO2 (variable to predict) by municipalities.
The environmental variables (EVI, LST, AOD) and NO2 represent average values from December 2018 to November 2019. The legends of all social variables show the count of people divided by 1000.
Table 1.
Municipality-level descriptive statistics of environmental variables for South Africa.
Table 2.
Municipality-level summary statistics of social variables for in South Africa.
Fig 3.
A bivariate relationship between NO2 and each explanatory socio-environmental variable across South African municipalities.
Fig 4.
The annual spatial distribution maps of standardized NO2 vertical column density; (a) Observed standardized NO2, (b) Predicted standardized NO2, (c) Standardized residual map, (d) Scatterplot of the relationship between the observed and predicted standardized NO2.
Fig 5.
Spatial distributions of coefficients (parameter estimates) of variables used to predict NO2 vertical column density.
Variations of green colour show the negative (opposite) influence of a variable on NO2, while the yellow-to-red colour scheme shows the positive influence on NO2.