Advances in Meteorology / 2015 / Article / Tab 2

Research Article

Analysis of Changes in Precipitation and Drought in Aksu River Basin, Northwest China

Table 2

Drought classification of SPI.

Drought classSPI value

NondroughtSPI ≥ 0
Near normal−1 < SPI < 0
Moderate−1.5 < SPI ≤ −1
Severe/extremeSPI ≤ −1.5