Level

Anomaly percentage

Types of drought and flood

1

M ≥ 75%

Particularly severe waterlogging

2

50% ≤ M < 75%

Flood

3

25% ≤ M < 50%

Partial waterlogging

4

−25% < M < 25%

normal

5

−50% < M ≤ −25%

Drought

6

−75% < M ≤ −50%

Severe drought

7

M ≤ −75%

Particularly severe drought