Figure 8 shows the weighted average FDCs, where the proportions (Table 5) are applied to the discerned FDCs for deficit and non-deficit years (Figure 6). The discrepancies in the average FDCs for different scenarios are rather large, especially for low durations (Table 6). An example in Figure 9 clearly illustrates the discrepancies for the 10% low duration. As FDC is one of the basic tools for water management, the identified range of uncertainties may be useful for risk assessment studies.
Table 6
Runoff (m3/s) for different durations at present and for the GCM scenarios
| GCMs | ||||||||
|---|---|---|---|---|---|---|---|---|
| Duration (%) | Present | CanESM2 | CCSM4 | CNRM-CM5 | GFDL-ESM2M | MIROC-ESM | MIROC-ESM-CHEM | NorESM1-M |
| Weihe | ||||||||
| 90 | 32.3 | 23.2 | 27.9 | 23.5 | 26.0 | 21.6 | 23.0 | 32.6 |
| 75 | 59.1 | 43.3 | 51.5 | 43.8 | 48.1 | 40.5 | 42.9 | 59.6 |
| 50 | 118.5 | 85.6 | 102.5 | 86.6 | 95.5 | 79.6 | 84.6 | 119.5 |
| 25 | 235.8 | 167.3 | 202.6 | 169.4 | 188.1 | 154.8 | 165.2 | 237.9 |
| 10 | 445.1 | 312.1 | 380.6 | 316.2 | 352.4 | 288.0 | 308.1 | 449.1 |
| Beijiang | ||||||||
| 90 | 259.7 | 276.6 | 228.8 | 292.6 | 243.3 | 290.4 | 230.9 | 269.4 |
| 75 | 362.5 | 396.2 | 301.0 | 427.9 | 329.9 | 423.6 | 305.3 | 381.8 |
| 50 | 630.2 | 698.8 | 504.9 | 763.4 | 563.6 | 754.6 | 513.7 | 669.4 |
| 25 | 1,274.6 | 1,406.8 | 1,033.0 | 1,531.4 | 1,146.3 | 1,514.4 | 1,050.0 | 1,350.1 |
| 10 | 2,468.3 | 2,709.0 | 2,028.1 | 2,935.9 | 2,234.4 | 2,905.0 | 2,059.0 | 2,605.8 |
| Qingjiang | ||||||||
| 90 | 47.5 | 44.0 | 42.7 | 46.7 | 43.4 | 48.8 | 43.2 | 48.0 |
| 75 | 72.0 | 64.8 | 62.0 | 70.3 | 63.5 | 74.7 | 63.1 | 73.0 |
| 50 | 139.2 | 123.3 | 117.2 | 135.3 | 120.5 | 145.1 | 119.6 | 141.4 |
| 25 | 298.5 | 257.0 | 241.2 | 288.5 | 249.7 | 314.0 | 247.3 | 304.3 |
| 10 | 643.9 | 535.0 | 493.7 | 617.6 | 516.0 | 684.4 | 509.6 | 658.9 |
| GCMs | ||||||||
|---|---|---|---|---|---|---|---|---|
| Duration (%) | Present | CanESM2 | CCSM4 | CNRM-CM5 | GFDL-ESM2M | MIROC-ESM | MIROC-ESM-CHEM | NorESM1-M |
| Weihe | ||||||||
| 90 | 32.3 | 23.2 | 27.9 | 23.5 | 26.0 | 21.6 | 23.0 | 32.6 |
| 75 | 59.1 | 43.3 | 51.5 | 43.8 | 48.1 | 40.5 | 42.9 | 59.6 |
| 50 | 118.5 | 85.6 | 102.5 | 86.6 | 95.5 | 79.6 | 84.6 | 119.5 |
| 25 | 235.8 | 167.3 | 202.6 | 169.4 | 188.1 | 154.8 | 165.2 | 237.9 |
| 10 | 445.1 | 312.1 | 380.6 | 316.2 | 352.4 | 288.0 | 308.1 | 449.1 |
| Beijiang | ||||||||
| 90 | 259.7 | 276.6 | 228.8 | 292.6 | 243.3 | 290.4 | 230.9 | 269.4 |
| 75 | 362.5 | 396.2 | 301.0 | 427.9 | 329.9 | 423.6 | 305.3 | 381.8 |
| 50 | 630.2 | 698.8 | 504.9 | 763.4 | 563.6 | 754.6 | 513.7 | 669.4 |
| 25 | 1,274.6 | 1,406.8 | 1,033.0 | 1,531.4 | 1,146.3 | 1,514.4 | 1,050.0 | 1,350.1 |
| 10 | 2,468.3 | 2,709.0 | 2,028.1 | 2,935.9 | 2,234.4 | 2,905.0 | 2,059.0 | 2,605.8 |
| Qingjiang | ||||||||
| 90 | 47.5 | 44.0 | 42.7 | 46.7 | 43.4 | 48.8 | 43.2 | 48.0 |
| 75 | 72.0 | 64.8 | 62.0 | 70.3 | 63.5 | 74.7 | 63.1 | 73.0 |
| 50 | 139.2 | 123.3 | 117.2 | 135.3 | 120.5 | 145.1 | 119.6 | 141.4 |
| 25 | 298.5 | 257.0 | 241.2 | 288.5 | 249.7 | 314.0 | 247.3 | 304.3 |
| 10 | 643.9 | 535.0 | 493.7 | 617.6 | 516.0 | 684.4 | 509.6 | 658.9 |
Figure 8
Average FDCs under different scenarios.
Figure 9
Differences (%) in the runoff with the 10% duration between the FDCs under different scenarios.