Class | Type of relief | Ds |
R1 | Very low relief | Ds < 10 m |
R2 | Low relief | 10 < Ds< 25 m |
R3 | Fairly low relief | 25 < Ds< 50 m |
R4 | Moderate relief | 50 < Ds< 100 m |
R5 | Fairly strong relief | 100 < Ds< 250 m |
R6 | Strong relief | 250 < Ds< 500 m |
R7 | Very strong relief | 500 m < Ds |