Figure 1.
Map showing locations of the Yangtze River (blue thick line), 7 gauging stations (black triangle points), 206 meteorological stations (black circle points), and the Three Gorges Dam (TGD).
Figure 1.
Map showing locations of the Yangtze River (blue thick line), 7 gauging stations (black triangle points), 206 meteorological stations (black circle points), and the Three Gorges Dam (TGD).
Figure 2.
Flowchart of reconstructed discharge modeling in the downstream from the TGD. CT: Cuntan, WL: Wulong, YC: Yichang, LS: Luoshan, HK: Hankou, JJ: Jiujiang, DT: Datong, OB: observed, RE: reconstructed, XAJ model: Xin’anjiang model; MSKG model: Muskingum routing model.
Figure 2.
Flowchart of reconstructed discharge modeling in the downstream from the TGD. CT: Cuntan, WL: Wulong, YC: Yichang, LS: Luoshan, HK: Hankou, JJ: Jiujiang, DT: Datong, OB: observed, RE: reconstructed, XAJ model: Xin’anjiang model; MSKG model: Muskingum routing model.
Figure 3.
Calibration period from 1 May 1990 to 31 December 1999.
Figure 3.
Calibration period from 1 May 1990 to 31 December 1999.
Figure 4.
Validation period from 1 January 2000 to 31 December 2002.
Figure 4.
Validation period from 1 January 2000 to 31 December 2002.
Figure 5.
Simulation period from 1 January 2003 to 31 December 2018.
Figure 5.
Simulation period from 1 January 2003 to 31 December 2018.
Figure 6.
Analysis of the maximum 1-day discharge during flood season in the five gauging stations (the grey zones denote the initial operation period of the TGD from 2003 to 2008, and the yellow zones denote the full operation period of the TGD from 2009 to 2018).
Figure 6.
Analysis of the maximum 1-day discharge during flood season in the five gauging stations (the grey zones denote the initial operation period of the TGD from 2003 to 2008, and the yellow zones denote the full operation period of the TGD from 2009 to 2018).
Figure 7.
Comparison of the maximum 1-day discharge during flood season between the five gauging stations. If points are above the 1:1 line, the reconstructed discharge is greater than the observed discharge, and the TGD has reduced the maximum 1-day discharge. In contrast, if points are below the 1:1 line, the reconstructed discharge is less than the observed discharge, and the TGD has increased the maximum 1-day discharge.
Figure 7.
Comparison of the maximum 1-day discharge during flood season between the five gauging stations. If points are above the 1:1 line, the reconstructed discharge is greater than the observed discharge, and the TGD has reduced the maximum 1-day discharge. In contrast, if points are below the 1:1 line, the reconstructed discharge is less than the observed discharge, and the TGD has increased the maximum 1-day discharge.
Figure 8.
The TGD’s impact on five gauging stations after its full operation based on an analysis of the maximum 1-day discharge. These results were calculated from the average of the difference between the observed maximum 1-day discharge and the reconstructed maximum 1-day discharge after the full operation of the TGD (see
Table 3 and
Table 4). The TGD’s impact on the Luoshan, Hankou, Jiujiang, and Datong gauging stations was calculated by the Muskingum routing model based on the TGD’s impact on the Yichang gauging station, assuming that the Yichang gauging station is completely controlled by the TGD.
Figure 8.
The TGD’s impact on five gauging stations after its full operation based on an analysis of the maximum 1-day discharge. These results were calculated from the average of the difference between the observed maximum 1-day discharge and the reconstructed maximum 1-day discharge after the full operation of the TGD (see
Table 3 and
Table 4). The TGD’s impact on the Luoshan, Hankou, Jiujiang, and Datong gauging stations was calculated by the Muskingum routing model based on the TGD’s impact on the Yichang gauging station, assuming that the Yichang gauging station is completely controlled by the TGD.
Figure 9.
Analysis of the maximum 30-day runoff during flood season in the five gauging stations (the grey zones denote the initial operation period of the TGD from 2003 to 2008, and the yellow zone denotes the full operation period of the TGD from 2009 to 2018).
Figure 9.
Analysis of the maximum 30-day runoff during flood season in the five gauging stations (the grey zones denote the initial operation period of the TGD from 2003 to 2008, and the yellow zone denotes the full operation period of the TGD from 2009 to 2018).
Figure 10.
Comparison of the maximum 30-day runoff during flood season between the five gauging stations. If points are above the 1:1 line, the reconstructed runoff is greater than the observed runoff, and the TGD has reduced the maximum 30-day runoff. In contrast, if points are below the 1:1 line, the reconstructed runoff is less than the observed runoff, and the TGD has increased the maximum 30-day runoff.
Figure 10.
Comparison of the maximum 30-day runoff during flood season between the five gauging stations. If points are above the 1:1 line, the reconstructed runoff is greater than the observed runoff, and the TGD has reduced the maximum 30-day runoff. In contrast, if points are below the 1:1 line, the reconstructed runoff is less than the observed runoff, and the TGD has increased the maximum 30-day runoff.
Figure 11.
The TGD’s impact on five gauging stations based on an analysis of the maximum 30-day runoff. These results were calculated from the average of the difference between the observed maximum 30-day runoff and the reconstructed maximum 30-day runoff after the full operation of the TGD (see
Table 5). The TGD’s impact on the Luoshan, Hankou, Jiujiang, and Datong gauging stations is equal to the TGD’s impact on the Yichang gauging station, assuming that the Yichang gauging station is completely controlled by the TGD.
Figure 11.
The TGD’s impact on five gauging stations based on an analysis of the maximum 30-day runoff. These results were calculated from the average of the difference between the observed maximum 30-day runoff and the reconstructed maximum 30-day runoff after the full operation of the TGD (see
Table 5). The TGD’s impact on the Luoshan, Hankou, Jiujiang, and Datong gauging stations is equal to the TGD’s impact on the Yichang gauging station, assuming that the Yichang gauging station is completely controlled by the TGD.
Figure 12.
Analysis of the flood season runoff in the five gauging stations (the grey zones denote the initial operation period of the TGD from 2003 to 2008, and the yellow zones denote the full operation period of the TGD from 2009 to 2018).
Figure 12.
Analysis of the flood season runoff in the five gauging stations (the grey zones denote the initial operation period of the TGD from 2003 to 2008, and the yellow zones denote the full operation period of the TGD from 2009 to 2018).
Figure 13.
Comparison of the flood season runoff during flood season between the five gauging stations. If points are above the 1:1 line, the reconstructed runoff is greater than the observed runoff, and the TGD has reduced the flood season runoff. In contrast, if points are below the 1:1 line, the reconstructed runoff is less than the observed runoff, and the TGD has increased the flood season runoff.
Figure 13.
Comparison of the flood season runoff during flood season between the five gauging stations. If points are above the 1:1 line, the reconstructed runoff is greater than the observed runoff, and the TGD has reduced the flood season runoff. In contrast, if points are below the 1:1 line, the reconstructed runoff is less than the observed runoff, and the TGD has increased the flood season runoff.
Figure 14.
The TGD’s impact on five gauging stations based on an analysis of the flood season runoff. These results were calculated from the average of the difference between the observed flood season runoff and the reconstructed flood season runoff after the full operation of the TGD (see
Table 6). The TGD’s impact on the Luoshan, Hankou, Jiujiang, and Datong gauging stations is equal to the TGD’s impact on the Yichang gauging station, assuming that the Yichang gauging station is completely controlled by the TGD.
Figure 14.
The TGD’s impact on five gauging stations based on an analysis of the flood season runoff. These results were calculated from the average of the difference between the observed flood season runoff and the reconstructed flood season runoff after the full operation of the TGD (see
Table 6). The TGD’s impact on the Luoshan, Hankou, Jiujiang, and Datong gauging stations is equal to the TGD’s impact on the Yichang gauging station, assuming that the Yichang gauging station is completely controlled by the TGD.
Figure 15.
Analysis of and of daily discharge during flood season in the five gauging stations (the grey zones denote the initial operation period of the TGD from 2003 to 2008, and the yellow zones denote the full operation period of the TGD from 2009 to 2018).
Figure 15.
Analysis of and of daily discharge during flood season in the five gauging stations (the grey zones denote the initial operation period of the TGD from 2003 to 2008, and the yellow zones denote the full operation period of the TGD from 2009 to 2018).
Figure 16.
Comparison of the and of daily discharge during flood season between the five gauging stations. If points are above the 1:1 line, the of reconstructed daily discharge is greater than the of the observed daily discharge, and the TGD has reduced the . In contrast, if points are below the 1:1 line, the of the reconstructed daily discharge is less than the of the observed daily discharge, and the TGD has increased the .
Figure 16.
Comparison of the and of daily discharge during flood season between the five gauging stations. If points are above the 1:1 line, the of reconstructed daily discharge is greater than the of the observed daily discharge, and the TGD has reduced the . In contrast, if points are below the 1:1 line, the of the reconstructed daily discharge is less than the of the observed daily discharge, and the TGD has increased the .
Figure 17.
Average monthly runoff during flood season after the full operation of the TGD.
Figure 17.
Average monthly runoff during flood season after the full operation of the TGD.
Figure 18.
Daily discharge at the Yichang gauging station during flood season in 2008.
Figure 18.
Daily discharge at the Yichang gauging station during flood season in 2008.
Table 1.
The distances of the gauging stations from the TGD (km) and their drainage area (km2). A negative distance value indicates that the gauging station is located upstream from the TGD, and a positive value indicates the gauging station is located downstream from the TGD. (* Wulong gauging station is located on the Wu River, a tributary of the Yangtze River).
Table 1.
The distances of the gauging stations from the TGD (km) and their drainage area (km2). A negative distance value indicates that the gauging station is located upstream from the TGD, and a positive value indicates the gauging station is located downstream from the TGD. (* Wulong gauging station is located on the Wu River, a tributary of the Yangtze River).
Station | Cuntan | Wulong * | Yichang | Luoshan | Hankou | Jiujiang | Datong |
---|
Distance | −597 | −543 | 43 | 452 | 643 | 877 | 1123 |
Area | 866,559 | 83,035 | 1,005,501 | 1,294,911 | 1,488,036 | 1,759,349 | 1,705,383 |
Table 2.
The Nash efficiency coefficient (NSE) of different gauging stations during different periods. Calibration period: 1990–1999; validation period: 2000–2002; simulation period: 2003–2018; initial operation of the TGD period: 2003–2008; full operation of the TGD period: 2009–2018.
Table 2.
The Nash efficiency coefficient (NSE) of different gauging stations during different periods. Calibration period: 1990–1999; validation period: 2000–2002; simulation period: 2003–2018; initial operation of the TGD period: 2003–2008; full operation of the TGD period: 2009–2018.
Period | Yichang | Luoshan | Hankou | Jiujiang | Datong | Average |
---|
1990–1999 | 0.993 | 0.981 | 0.983 | 0.979 | 0.973 | 0.982 |
2000–2002 | 0.992 | 0.978 | 0.978 | 0.964 | 0.963 | 0.975 |
2003–2018 | 0.890 | 0.943 | 0.893 | 0.931 | 0.835 | 0.898 |
2003–2008 | 0.953 | 0.942 | 0.952 | 0.944 | 0.895 | 0.937 |
2009–2018 | 0.838 | 0.867 | 0.852 | 0.832 | 0.801 | 0.838 |
Table 3.
The difference between the reconstructed maximum 1-day discharge and the observed maximum 1-day discharge after the full operation of the TGD from 2009 to 2018. If the difference is greater than 0, the TGD has reduced the maximum 1-day discharge during flood season. Difference = QRe − QOb; QRe: reconstructed maximum 1-day discharge; QOb: observed maximum 1-day discharge.
Table 3.
The difference between the reconstructed maximum 1-day discharge and the observed maximum 1-day discharge after the full operation of the TGD from 2009 to 2018. If the difference is greater than 0, the TGD has reduced the maximum 1-day discharge during flood season. Difference = QRe − QOb; QRe: reconstructed maximum 1-day discharge; QOb: observed maximum 1-day discharge.
Year | Yichang | Luoshan | Hankou | Jiujiang | Datong |
---|
2009 | 11,517 | 6946 | 5408 | 5652 | 5006 |
2010 | 16,838 | 11,106 | 2737 | 6920 | 13,292 |
2011 | 10,585 | 7127 | 7470 | 8001 | 14,673 |
2012 | 11,453 | 8785 | 10,269 | 12,575 | 19,931 |
2013 | 6766 | 6153 | 5589 | 6935 | 5741 |
2014 | 531 | 4942 | 7367 | 8074 | 15,058 |
2015 | 2324 | 3852 | 6479 | 5557 | 10,369 |
2016 | 6662 | 5751 | 7837 | 9610 | 17,332 |
2017 | 3099 | 3431 | 8317 | 10,458 | 12,361 |
2018 | 10,972 | 9147 | 11,681 | 12,571 | 18,089 |
Average | 8074.7 | 6724.0 | 7315.4 | 8635.3 | 13,185.2 |
Table 4.
The difference between the reconstructed maximum 1-day discharge and the observed maximum 1-day discharge at the Yichang gauging station was routed to the four gauging stations downstream from the Yichang gauging station by using the Muskingum model. If the difference is greater than 0, the TGD has reduced the maximum 1-day discharge during flood season.
Table 4.
The difference between the reconstructed maximum 1-day discharge and the observed maximum 1-day discharge at the Yichang gauging station was routed to the four gauging stations downstream from the Yichang gauging station by using the Muskingum model. If the difference is greater than 0, the TGD has reduced the maximum 1-day discharge during flood season.
Year | Luoshan | Hankou | Jiujiang | Datong |
---|
2009 | 4012 | 3244 | 3179 | 2070 |
2010 | 6118 | 5164 | 5127 | 5161 |
2011 | 5186 | 4652 | 4577 | 3777 |
2012 | 2775 | 2064 | 2125 | 1615 |
2013 | 3244 | 2875 | 2811 | 2139 |
2014 | 1151 | 1626 | 1633 | 1877 |
2015 | 1727 | 1987 | 1991 | 2762 |
2016 | 3863 | 2987 | 2867 | 1041 |
2017 | 1331 | 1058 | 1052 | 475 |
2018 | 4355 | 4026 | 3965 | 3203 |
Average | 3376.0 | 2968.2 | 2932.6 | 2412.0 |
Table 5.
The difference between the observed maximum 30-day runoff and the reconstructed maximum 30-day runoff after the full operation of the TGD from 2009 to 2018. If the difference is greater than 0, the TGD has reduced the maximum 30-day runoff during flood season. Difference = RRe − ROb; RRe: reconstructed maximum 30-day runoff; ROb: observed maximum 30-day runoff.
Table 5.
The difference between the observed maximum 30-day runoff and the reconstructed maximum 30-day runoff after the full operation of the TGD from 2009 to 2018. If the difference is greater than 0, the TGD has reduced the maximum 30-day runoff during flood season. Difference = RRe − ROb; RRe: reconstructed maximum 30-day runoff; ROb: observed maximum 30-day runoff.
Year | Yichang | Luoshan | Hankou | Jiujiang | Datong |
---|
2009 | 27.6 | 39.3 | 46.5 | 41.8 | 47.0 |
2010 | 77.1 | 110.0 | 51.8 | 51.1 | 229.2 |
2011 | 52.3 | 108.5 | 125.6 | 122.1 | 231.9 |
2012 | 72.2 | 165.0 | 178.8 | 217.7 | 377.6 |
2013 | 24.2 | 105.6 | 86.2 | 137.9 | 183.5 |
2014 | 75.5 | 97.1 | 147.6 | 169.2 | 290.1 |
2015 | 90.5 | 56.3 | 124.6 | 149.6 | 311.5 |
2016 | 46.9 | 124.6 | 209.7 | 230.8 | 366.0 |
2017 | 42.7 | 70.6 | 191.0 | 242.2 | 255.6 |
2018 | 23.6 | 132.5 | 185.1 | 211.4 | 302.5 |
Average | 53.27 | 100.97 | 134.68 | 157.38 | 259.50 |
Table 6.
The difference between the observed flood season runoff and the reconstructed flood season runoff after the full operation of the TGD from 2009 to 2018. If the difference is less than 0, the TGD has increased the flood season runoff. Difference = RRe − ROb; RRe: reconstructed flood season runoff; ROb: observed flood season runoff.
Table 6.
The difference between the observed flood season runoff and the reconstructed flood season runoff after the full operation of the TGD from 2009 to 2018. If the difference is less than 0, the TGD has increased the flood season runoff. Difference = RRe − ROb; RRe: reconstructed flood season runoff; ROb: observed flood season runoff.
Year | Yichang | Luoshan | Hankou | Jiujiang | Datong |
---|
2009 | 175.82 | 297.79 | 275.62 | 212.26 | 195.26 |
2010 | 190.00 | 326.24 | 352.60 | 331.87 | 650.10 |
2011 | 320.69 | 542.67 | 369.60 | 427.08 | 582.98 |
2012 | 112.83 | 309.75 | 539.03 | 576.43 | 936.16 |
2013 | 144.10 | 327.03 | 259.32 | 485.05 | 661.94 |
2014 | 70.51 | 439.70 | 586.80 | 746.10 | 1031.43 |
2015 | 163.41 | 647.71 | 853.71 | 956.58 | 1517.10 |
2016 | 153.77 | 452.01 | 996.62 | 994.65 | 1326.63 |
2017 | 119.85 | 665.01 | 1027.91 | 1201.99 | 1524.93 |
2018 | 81.39 | 445.33 | 694.77 | 766.91 | 810.93 |
Average | 153.24 | 445.32 | 595.60 | 669.89 | 923.75 |