| Materials | Shape parameter (k) | Scale parameter (λ) | R2 | |
| silty sand | Fine (<0.80 mm) | 2.89 | 0.44 | 0.98 |
| coarse (>0.80 mm) | 0.70 | 0.28 | 0.99 | |
| White glass sand | Fine (<0.80 mm) | 2.50 | 0.42 | 0.99 |
| coarse (>0.80 mm) | 0.52 | 0.08 | 0.98 | |
| Green glass sand | 1.82 | 0.41 | 0.98 | |
| Brown glass sand | 1.96 | 0.57 | 0.98 | |