Table 3.
Correlation of spatial predictors to mean station PM2.5 under stable conditions.
| Spatial predictor | Correlation coefficient |
|---|---|
| Population density | 0.722 |
| 700 m local minima fct. | −0.605 |
| 10 km local minima fct. | −0.561 |
| 15 km local minima fct | −0.559 |
| 20 km local minima fct | −0.551 |
| 2500 m local minima fct. | −0.543 |
| 25 km local minima fct. | −0.543 |
| 5 km local minima fct. | −0.499 |
| 50 km local minima fct. | −0.499 |
| industrial land | 0.345 |
| Long-haul trucking | 0.340 |
These predictors were used to inform the model of static smog potential. Population density was consistently the best predictor of surface PM2.5 pollution under such conditions.