等级

分类

SPI

0

接近正常

−0.5 < SPI ≤ 0.5

1

轻旱

−1.00 < SPI ≤ −0.5

2

中旱

−1.50 < SPI ≤ −1.00

3

重旱

−2.00 < SPI ≤ −1.50

4

极旱

SPI ≤ −2.00