SPEI-Based Spatiotemporal Analysis of Drought in Haihe River Basin from 1961 to 2010

Table 1

Classification standard of drought based on SPEI.

No drought	Light drought	Moderate drought	Severe drought	Extreme drought
−0.5 < SPEI	−1 < SPEI ≤ −0.5	−1.5 < SPEI ≤ −1	−2 < SPEI ≤ −1.5	SPEI ≤ −2