Table 6.
Semivariogram analysis of the concentration of soil potentially toxic elements (0–0.2 m) in the municipality of Barcarena, Brazilian Amazon.
| Variable | Model | Nugget | Spatial Variance | Sill | Range (m) | SDI | SDI (Classification) | R2 |
|---|---|---|---|---|---|---|---|---|
| As | Spherical | 1 | 1.25 | 2.25 | 1000 | 0.44 | Moderate | 0.99 |
| Ba | Spherical | 35 | 55 | 90.00 | 1300 | 0.39 | Moderate | 0.99 |
| Pb | Spherical | 20 | 49 | 69.00 | 950 | 0.29 | Strong | 0.98 |
| Co | Spherical | 0.3 | 0.36 | 0.66 | 700 | 0.41 | Moderate | 0.98 |
| Cu | Spherical | 0 | 850 | 850.00 | 780 | 0 | Strong | 0.97 |
| Cr | Spherical | 40 | 67 | 107.00 | 1000 | 0.37 | Moderate | 0.99 |
| Hg | Spherical | 0 | 0.02 | 0.02 | 900 | 0 | Strong | 0.94 |
| Ni | Spherical | 0 | 13.3 | 13.30 | 1700 | 0 | Strong | 0.99 |
| Zn | Spherical | 0 | 1140 | 1140 | 1200 | 0 | Strong | 0.99 |
SDI: Spatial Dependence Index.