Figure 1.
Incremental basin areas of the Orós (a), Banabuiú (b) and Castanhão (c) reservoirs. Source COGERH.
Figure 1.
Incremental basin areas of the Orós (a), Banabuiú (b) and Castanhão (c) reservoirs. Source COGERH.
Figure 2.
Water management in Ceará State, showing the Ceará State inflow forecast system schematic depicting January–April (rainy period) forecasts. The forecast system schematic includes (1) statistical models using previous July and October equatorial Pacific and Atlantic indices and (2) monthly precipitation forecasts from dynamical global and regional seasonal forecast models updated monthly from January to April. The models and forecasts feed a hydrological model to generate monthly flow forecasts (brown) and ECMWF subseasonal precipitation forecasts produced every Thursday for the following 45 days. The results of this model feed a hydrological model to generate daily flow forecasts during the January–May period (yellow). The blue (gray) bar indicates the wet (dry) period [
39]; © American Meteorological Society. Used with permission.
Figure 2.
Water management in Ceará State, showing the Ceará State inflow forecast system schematic depicting January–April (rainy period) forecasts. The forecast system schematic includes (1) statistical models using previous July and October equatorial Pacific and Atlantic indices and (2) monthly precipitation forecasts from dynamical global and regional seasonal forecast models updated monthly from January to April. The models and forecasts feed a hydrological model to generate monthly flow forecasts (brown) and ECMWF subseasonal precipitation forecasts produced every Thursday for the following 45 days. The results of this model feed a hydrological model to generate daily flow forecasts during the January–May period (yellow). The blue (gray) bar indicates the wet (dry) period [
39]; © American Meteorological Society. Used with permission.
Figure 3.
Conceptual diagram of monthly SMAP model. Flow direction of streamflow, evaporation, and precipitation are indicated by arrows. Source [
40].
Figure 3.
Conceptual diagram of monthly SMAP model. Flow direction of streamflow, evaporation, and precipitation are indicated by arrows. Source [
40].
Figure 4.
Pearson correlation coefficients (CORR) for the ensemble mean of cumulative rainfall forecasts for JFMAM from the ECHAM4.6 model and CMAP (observed) for Northeast Brazil between 1981 and 2010.
Figure 4.
Pearson correlation coefficients (CORR) for the ensemble mean of cumulative rainfall forecasts for JFMAM from the ECHAM4.6 model and CMAP (observed) for Northeast Brazil between 1981 and 2010.
Figure 5.
Forecasts from the ECHAM4.6 model (boxplots) for cumulative rainfall for JFMAM during the hindcast period for the (a) Orós Reservoir, (b) Banabuiú Reservoir, and (c) Castanhão Reservoir. The dotted horizontal lines represent the 33 and 66 percentiles of the observed climatology, with the categories below average, around average, and above average represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the observed values of cumulative rainfall.
Figure 5.
Forecasts from the ECHAM4.6 model (boxplots) for cumulative rainfall for JFMAM during the hindcast period for the (a) Orós Reservoir, (b) Banabuiú Reservoir, and (c) Castanhão Reservoir. The dotted horizontal lines represent the 33 and 66 percentiles of the observed climatology, with the categories below average, around average, and above average represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the observed values of cumulative rainfall.
Figure 6.
Forecasts from the ECHAM4.6 model (boxplots) for cumulative rainfall for JFMAM during the verification period for the (a) Orós Reservoir, (b) Banabuiú Reservoir, and (c) Castanhão Reservoir. The dotted horizontal lines represent the 33 and 66 percentiles of the observed climatology, with the categories below average, around average, and above average represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the observed values of cumulative rainfall.
Figure 6.
Forecasts from the ECHAM4.6 model (boxplots) for cumulative rainfall for JFMAM during the verification period for the (a) Orós Reservoir, (b) Banabuiú Reservoir, and (c) Castanhão Reservoir. The dotted horizontal lines represent the 33 and 66 percentiles of the observed climatology, with the categories below average, around average, and above average represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the observed values of cumulative rainfall.
Figure 7.
Streamflow forecasts (boxplots) corresponding to the 20 rainfall members of the ECHAM4.6 model, obtained from the SMAP model during the JFMAM period for the (a) Orós Reservoir, (b) Banabuiú Reservoir, and (c) Castanhão Reservoir for the hindcast period. The horizontal dotted lines represent the 33 and 66 percentiles of the observed climatology, with the categories below average, around average, and above average represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the estimated streamflow values for the JFMAM period.
Figure 7.
Streamflow forecasts (boxplots) corresponding to the 20 rainfall members of the ECHAM4.6 model, obtained from the SMAP model during the JFMAM period for the (a) Orós Reservoir, (b) Banabuiú Reservoir, and (c) Castanhão Reservoir for the hindcast period. The horizontal dotted lines represent the 33 and 66 percentiles of the observed climatology, with the categories below average, around average, and above average represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the estimated streamflow values for the JFMAM period.
Figure 8.
Streamflow forecasts (boxplots) corresponding to the 20 rainfall members of the ECHAM4.6 model, obtained from the SMAP model for the JFMAM period for the (a) Orós Reservoir, (b) Banabuiú Reservoir, and (c) Castanhão Reservoir for the forecast period. The horizontal dotted lines represent the 33 and 66 percentiles of the observed climatology, with the categories below average, around average, and above average represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the estimated streamflow values for the JFMAM period.
Figure 8.
Streamflow forecasts (boxplots) corresponding to the 20 rainfall members of the ECHAM4.6 model, obtained from the SMAP model for the JFMAM period for the (a) Orós Reservoir, (b) Banabuiú Reservoir, and (c) Castanhão Reservoir for the forecast period. The horizontal dotted lines represent the 33 and 66 percentiles of the observed climatology, with the categories below average, around average, and above average represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the estimated streamflow values for the JFMAM period.
Figure 9.
Volumes of the identified reservoirs at the end of December, beginning with 10% capacity at the beginning of January, from the simulated operation of the reservoirs to meet demands based on streamflow forecasts (boxplots) for the hindcast period: (a) Orós, (b) Banabuiú, and (c) Castanhão. The dotted horizontal lines represent the 33 and 66 percentiles referring to the resulting volumes at the end of December for the same period (JFMAM) during the verification period. The categories below average, around average, and above average are represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the volumes at the end of the month of December based on simulated operations using streamflow observed for the JFMAM period, while the black dots are the simulated operations using the hypothetical zero streamflow into the reservoirs.
Figure 9.
Volumes of the identified reservoirs at the end of December, beginning with 10% capacity at the beginning of January, from the simulated operation of the reservoirs to meet demands based on streamflow forecasts (boxplots) for the hindcast period: (a) Orós, (b) Banabuiú, and (c) Castanhão. The dotted horizontal lines represent the 33 and 66 percentiles referring to the resulting volumes at the end of December for the same period (JFMAM) during the verification period. The categories below average, around average, and above average are represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the volumes at the end of the month of December based on simulated operations using streamflow observed for the JFMAM period, while the black dots are the simulated operations using the hypothetical zero streamflow into the reservoirs.
Figure 10.
Volumes of the identified reservoirs at the end of December, beginning with 10% capacity at the beginning of January, from the simulated operation of the reservoirs to meet demands based on streamflow forecasts (boxplots) for the verification period: (a) Orós, (b) Banabuiú, and (c) Castanhão. The dotted horizontal lines represent the 33 and 66 percentiles referring to the resulting volumes at the end of December for the same period (JFMAM) during the verification period. The categories below average, around average, and above average are represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the volumes at the end of the month of December based on simulated operations using streamflow observed for the JFMAM period, while the black dots are the simulated operations using the hypothetical zero streamflow into the reservoirs.
Figure 10.
Volumes of the identified reservoirs at the end of December, beginning with 10% capacity at the beginning of January, from the simulated operation of the reservoirs to meet demands based on streamflow forecasts (boxplots) for the verification period: (a) Orós, (b) Banabuiú, and (c) Castanhão. The dotted horizontal lines represent the 33 and 66 percentiles referring to the resulting volumes at the end of December for the same period (JFMAM) during the verification period. The categories below average, around average, and above average are represented by the colors orange, green, and blue colored shaded areas, respectively. The red dots represent the volumes at the end of the month of December based on simulated operations using streamflow observed for the JFMAM period, while the black dots are the simulated operations using the hypothetical zero streamflow into the reservoirs.
Table 1.
Basic Data and Statistics for Accumulated Inflow of the Orós, Banabuiú, and Castanhão Reservoirs from January to June. Source COGERH.
Table 1.
Basic Data and Statistics for Accumulated Inflow of the Orós, Banabuiú, and Castanhão Reservoirs from January to June. Source COGERH.
| Reservoir |
---|
Orós | Banabuiú | Castanhão |
---|
Total Basin Area (km2) | 24,960.92 | 14,244.22 | 44,806.33 |
Storage (hm3) | 1940 | 1601 | 6700 |
Q10 (hm3) | 67.51 | 8.57 | 153.84 |
Q25 (hm3) | 129.08 | 27.15 | 199.17 |
Median (hm3) | 322.01 | 90.27 | 323.69 |
Q75 (hm3) | 758.72 | 535.05 | 1139.6 |
Q90 (hm3) | 1438.06 | 836.18 | 1904.24 |
Mean (hm3) | 628.21 | 331.48 | 877.16 |
Standard Deviation (hm3) | 831.6 | 495.61 | 1189.73 |
Table 2.
Nash–Sutcliffe Efficiency and correlation between observed and SMAP-modeled monthly inflows for the Orós, Banabuiú, and Castanhão Reservoirs.
Table 2.
Nash–Sutcliffe Efficiency and correlation between observed and SMAP-modeled monthly inflows for the Orós, Banabuiú, and Castanhão Reservoirs.
Reservoir | 1986–2010 | 2011–2022 | 1986–2022 |
---|
NSE | CORR | NSE | CORR | NSE | CORR |
---|
Orós | 0.81 | 0.95 | 0.28 | 0.96 | 0.80 | 0.95 |
Banabuiú | 0.45 | 0.66 | 0.50 | 0.80 | 0.52 | 0.70 |
Castanhão | 0.70 | 0.87 | 0.83 | 0.91 | 0.87 | 0.81 |
Table 3.
Evaluation of the performance metrics for the rainfall forecasts during the JFMAM period, using the ECHAM4.6 model for the contribution basins of the Orós, Banabuiú, and Castanhão Reservoirs.
Table 3.
Evaluation of the performance metrics for the rainfall forecasts during the JFMAM period, using the ECHAM4.6 model for the contribution basins of the Orós, Banabuiú, and Castanhão Reservoirs.
Reservoir | 1981–2010 | 2011–2022 | 1981–2022 |
---|
RPSS | CORR | RPSS | CORR | RPSS | CORR |
---|
Orós | 0.13 | 0.61 | 0.31 | 0.50 | 0.19 | 0.60 |
Banabuiú | 0.26 | 0.66 | 0.38 | 0.67 | 0.30 | 0.66 |
Castanhão | 0.16 | 0.64 | 0.32 | 0.66 | 0.21 | 0.66 |
Table 4.
The performance evaluation metrics for the streamflow forecasts for the Orós, Banabuiú, and Castanhão Reservoirs for the JFMAM period, obtained through the unidirectional coupling of the ECHAM4.6 model and the monthly SMAP hydrological model.
Table 4.
The performance evaluation metrics for the streamflow forecasts for the Orós, Banabuiú, and Castanhão Reservoirs for the JFMAM period, obtained through the unidirectional coupling of the ECHAM4.6 model and the monthly SMAP hydrological model.
Reservoir | 1981–2010 | 2011–2022 | 1981–2022 |
---|
NSE | RPSS | CORR | NSE | RPSS | CORR | NSE | RPSS | CORR |
---|
Orós | 0.69 | 0.19 | 0.82 | 0.12 | 0.43 | 0.47 | 0.68 | 0.25 | 0.81 |
Banabuiú | 0.72 | 0.24 | 0.83 | −1.40 | 0.18 | 0.71 | 0.66 | 0.22 | 0.81 |
Castanhão | 0.65 | 0.44 | 0.80 | 0.59 | 0.49 | 0.73 | 0.66 | 0.46 | 0.81 |
Table 5.
Performance evaluation metrics for the volumes at the end of May of the Orós, Banabuiú, and Castanhão Reservoirs, identified using the simulated operations of the reservoirs for forecasted and observed inflows into the reservoirs.
Table 5.
Performance evaluation metrics for the volumes at the end of May of the Orós, Banabuiú, and Castanhão Reservoirs, identified using the simulated operations of the reservoirs for forecasted and observed inflows into the reservoirs.
Reservoir | Initial Volume | 1981–2010 | 2011–2022 | 1981–2022 |
---|
RPSS | CORR | RPSS | CORR | RPSS | CORR |
---|
Orós | 10% | 0.24 | 0.73 | 0.26 | 0.47 | 0.25 | 0.73 |
25% | 0.24 | 0.69 | 0.26 | 0.47 | 0.24 | 0.70 |
50% | 0.27 | 0.64 | 0.26 | 0.48 | 0.27 | 0.65 |
Banabuiú | 10% | 0.25 | 0.79 | 0.46 | 0.69 | 0.31 | 0.78 |
25% | 0.25 | 0.76 | 0.46 | 0.69 | 0.31 | 0.75 |
50% | 0.23 | 0.69 | 0.43 | 0.69 | 0.29 | 0.69 |
Castanhão | 10% | 0.30 | 0.77 | 0.56 | 0.70 | 0.37 | 0.78 |
25% | 0.29 | 0.74 | 0.53 | 0.73 | 0.36 | 0.76 |
50% | 0.25 | 0.67 | 0.41 | 0.72 | 0.29 | 0.70 |
Table 6.
Average number of years in each range/percent of the demands met at the end of the December for the Orós, Banabuiú, and Castanhão Reservoirs, identified using the simulated operations for the forecasted and observed inflows into the reservoirs.
Table 6.
Average number of years in each range/percent of the demands met at the end of the December for the Orós, Banabuiú, and Castanhão Reservoirs, identified using the simulated operations for the forecasted and observed inflows into the reservoirs.
Reservoir | Info | % Demands Met at the end of December * |
---|
=0 | 0↔25 | 25→50 | 50→75 | 75→100 | =100 |
---|
Orós | Fcst. | 18.7 | 19.3 | 0.6 | 0.4 | 21.9 | 21.5 |
Obs. | 11 | 14 | 1 | 2 | 25 | 25 |
Banabuiú | Fcst. | 18.5 | 19.0 | 0.5 | 0.2 | 22.4 | 22.1 |
Obs. | 18 | 20 | 0 | 0 | 22 | 21 |
Castanhão | Fcst. | 15.6 | 16.7 | 0.4 | 0.6 | 24.3 | 23.8 |
Obs. | 9 | 12 | 0 | 0 | 30 | 30 |