| 类别 | 级差 | 级面积(km2) | 级比例(%) | 类面积(km2) | 类比例(%) | 
| 变差 | −4 | 1.62 | 0.04 | 688.26 | 16.7 | 
| −3 | 7.10 | 0.2 | |||
| −2 | 57.89 | 1.4 | |||
| −1 | 621.65 | 15.1 | |||
| 不变 | 0 | 2087.85 | 50.6 | 2087.85 | 50.6 | 
| 变好 | 1 | 899.51 | 21.8 | 1349.63 | 32.7 | 
| 2 | 427.04 | 10.4 | |||
| 3 | 23.00 | 0.6 | |||
| 4 | 0.08 | 0 |