IWA Publishing

Table 1

Drought classification based on SPEI value (McKee et al. 1993)

SPEI value	Condition	Class
≥2	Extremely wet	1
1.5 s/d 1.99	Wet	2
1.00 s/d 1.49	Moderately wet	3
0.99 s/d −0.99	Normal	4
−1.00 s/d −1.49	Moderately dry	5
−1.50 s/d −1.99	Dry	6
≤− 2	Extremely dry	7

SPEI value	Condition	Class
≥2	Extremely wet	1
1.5 s/d 1.99	Wet	2
1.00 s/d 1.49	Moderately wet	3
0.99 s/d −0.99	Normal	4
−1.00 s/d −1.49	Moderately dry	5
−1.50 s/d −1.99	Dry	6
≤− 2	Extremely dry	7