Comparing the FD of the EFC indicators of S1 and S2, the influence of the reservoir on the EFC parameters under S3 was quantitatively distinguished. The results show that the environmental flow in the MRYR is affected by the TGR as a whole by 42.1%. Yichang Station is most significantly affected by the reservoir, the relative contribution of the TGR is 52.6%, which exceeds the impact of natural factors (Table 6). Meanwhile, the TGR significantly changed the small flood events in the MRYR with a relative contribution of 56.2%, resulting in an increase in the peak, rise, and fall rates of small floods, significantly reduced duration, frequency, and slightly delayed timing, especially at Yichang Station (Figure 7).
Close modal
Table 6
The relative contribution of the TGR to EFCs
| EFC | Yichang | Luoshan | Hankou | Mean |
|---|---|---|---|---|
| Low-flow (%) | 62.7 | 48.6 | 42.7 | 51.3 |
| Extreme low-flow (%) | 44.2 | 45.3 | 37.6 | 42.4 |
| High-flow pulse (%) | 56.8 | 41.7 | 56.2 | 51.6 |
| Small flood (%) | 86.3 | 34.9 | 47.3 | 56.2 |
| Large flood (%) | 0.00 | 0.00 | 0.00 | 0.00 |
| ALL (%) | 52.6 | 36.0 | 37.7 | 42.1 |
| EFC | Yichang | Luoshan | Hankou | Mean |
|---|---|---|---|---|
| Low-flow (%) | 62.7 | 48.6 | 42.7 | 51.3 |
| Extreme low-flow (%) | 44.2 | 45.3 | 37.6 | 42.4 |
| High-flow pulse (%) | 56.8 | 41.7 | 56.2 | 51.6 |
| Small flood (%) | 86.3 | 34.9 | 47.3 | 56.2 |
| Large flood (%) | 0.00 | 0.00 | 0.00 | 0.00 |
| ALL (%) | 52.6 | 36.0 | 37.7 | 42.1 |
Figure 7
Contributions of TGR and changes in natural factors to the variation of 34 environmental flow indicators in the MRYR.
Figure 7
Contributions of TGR and changes in natural factors to the variation of 34 environmental flow indicators in the MRYR.