Table 4 Range of duration (number of months) of moderate, severe, and extreme drought events in the sub-basins
Sub-basin | Drought category | SPI-4 | SPEI-4 | SPI-12 | SPEI-12 |
|---|---|---|---|---|---|
Northern | Moderate | 37–47 | 43–55 | 31–45 | 42–61 |
Severe | 14–29 | 21–25 | 9–41 | 9–32 | |
Extreme | 5–15 | 2–6 | 6–17 | 1–9 | |
Central | Moderate | 33–54 | 46–55 | 29–62 | 35–59 |
Severe | 12–23 | 17–24 | 9–21 | 16–26 | |
Extreme | 3–18 | 2–7 | 1–16 | 0–12 | |
Southern | Moderate | 34–57 | 47–62 | 38–48 | 38–68 |
Severe | 16–29 | 17–29 | 8–47 | 19–22 | |
Extreme | 8–20 | 3–7 | 5–18 | 0–14 |