Regions | Yearly amount of rainfall (mm) | Yearly amount of run-off (mm) | Area (%) | Yearly amount of water resources (%) |
Arid | <200 | <10 | 26.6 | 2 |
Semi-arid | 200 - 400 | 10 - 50 | 20.9 | 5 |
Total |
|
| 47.5 | 7 |
Humid | 400 - 800 | 50 - 200 | 18.6 | 12 |
Semi-humid | 800 - 1600 | 200 - 800 | 26.0 | 58 |
Extremely humid | >2000 | >800 | 7.9 | 23 |
Total |
|
| 52.5 | 93 |