Criteria | Grade | Classes |
EP ≤ 300 mm/year | 1 | No effect |
300 mm/year < EP ≤ 600 mm/year | 2 | Low to medium effect |
600 mm/year < EP ≤ 800 mm/year | 3 | High effect |
EP > 800 mm/year | 4 | Very high effect |