## 4 Results and Discussion
### Water Balance Evaluation between 2020 and 2029
#### 4.7.3 Annual Water Balance with the Consideration of Ecological Water Requirements  
Table 26 reports the evaluation results of the annual water balance in terms of water surplus or deficit between 2020 and 2029 with the consideration of ecological water requirements in the two different scenarios and conditions.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Year**} & \multicolumn{2}{c}{**Water Supply (Million m\({}^{3}\))**} & \multicolumn{2}{c}{**Water Demand (Million m\({}^{3}\))**} & \multicolumn{2}{c}{**Water Balance (Million m\({}^{3}\))**} \\ \cline{2-9}  & \multirow{2}{*}{**Dry Year**} & \multirow{2}{*}{**Wet Year**} & \multirow{2}{*}{**Normal**} & \multirow{2}{*}{**New Normal**} & & **Dry Year** & \multicolumn{2}{c}{**Wet Year**} \\ \cline{5-8}  & & & & & **Normal** & **New Normal** & **New Normal** \\ \hline
2020 & 357.37 & 1077.84 & 475.86 & \(461.53\) & \(-118.49\) & \(-104.16\) & 601.97 & 616.31 \\
2021 & 358.09 & 1078.85 & \(469.19\) & 457.65 & \(-111.10\) & \(-99.56\) & 609.66 & 621.20 \\
2022 & 358.70 & 1079.64 & 466.45 & \(457.67\) & \(-107.75\) & \(-98.98\) & 613.19 & 621.96 \\
2023 & 359.77 & 1080.91 & 462.31 & 456.19 & \(-102.54\) & \(-96.43\) & 618.60 & 624.71 \\
2024 & 360.65 & 1081.54 & 460.77 & 460.77 & \(-100.13\) & \(-100.13\) & 620.77 & 620.77 \\
2025 & 362.43 & 1083.74 & 455.62 & 455.62 & \(-93.20\) & \(-93.20\) & 628.12 & 628.12 \\
2026 & 370.19 & 1090.69 & 452.48 & 452.48 & \(-82.29\) & \(-82.29\) & 638.20 & 638.20 \\
2027 & 371.92 & 1092.67 & 448.98 & 448.98 & \(-77.07\) & \(-77.07\) & 643.68 & 643.68 \\
2028 & 372.58 & 1093.30 & 447.29 & 447.29 & \(-74.71\) & \(-74.71\) & 646.01 & 646.01 \\
2029 & 374.15 & 1094.44 & 442.09 & 442.09 & \(-67.94\) & \(-67.94\) & 652.35 & 652.35 \\ \hline Average & 364.58 & 1085.36 & 458.11 & 454.03 & \(-93.52\) & \(-89.45\) & 627.26 & 631.33 \\ \hline \hline \end{tabular}
\end{table}
Table 26: The annual water supply and demand balance evaluation with the consideration of ecological water requirements between 2020 and 2029.  
Figure 15: Monthly water balance without the consideration of ecological water requirements under two scenarios in normal and new normal conditions: (**a**) dry year scenario; (**b**) wet year scenario.  
Under the dry year scenario, the annual water balance in the normal condition indicates a deficit in all years. It varies from 67.94 million m\({}^{3}\) to 118.49 million m\({}^{3}\), with an average water deficit of 93.52 million m\({}^{3}\). Similarly, the annual water balance in the new normal condition also shows a deficit in all years. It varies from 67.94 million m\({}^{3}\) to 104.16 million m\({}^{3}\), with an average water deficit of 89.45 million m\({}^{3}\).  
On the contrary, the annual water balance in the normal condition indicates a surplus in all years under the wet year scenario. It varies from 601.97 million m\({}^{3}\) to 652.35 million m\({}^{3}\), an average water surplus of 627.26 million m\({}^{3}\). Similarly, the annual water balance in the new normal condition also shows a surplus in all years. It varies from 616.31 million m\({}^{3}\) to 652.35 million m\({}^{3}\), with an average water surplus of 631.33 million m\({}^{3}\).