Table 1 The grade standards of the watershed lagged intensity and frequency.
Lagged intensity | Lagged frequency | ||
|---|---|---|---|
Level | Index (LI) | Level | Index (F) |
Nonlagged effect | 0.0 ≤ LI | Low frequency | 0–20% |
Mild lagged effect | − 1.0 ≤ LI < 0.0 | Medium–low frequency | 20–40% |
Moderate lagged effect | − 1.5 ≤ LI < − 1.0 | Medium frequency | 40–60% |
Severe lagged effect | − 2.0 ≤ LI < − 1.5 | Medium–high frequency | 60–80% |
Extreme lagged effect | LI < − 2.0 | High frequency | 80–100% |
