# Assessing Groundwater Level with a Unified Seasonal Outlook and Hydrological Modeling Projection
## 4 Results and Discussion
### Rainfall Generation by WGEN
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \begin{tabular}{c} **Xinpu** \\ **Station** \\ \end{tabular} & **2018** & \begin{tabular}{c} **Real Occurrence** \\ **(mm)** \\ \end{tabular} & \begin{tabular}{c} **25 th Percentile of** \\ **Simulation Rainfall** \\ **(mm)** \\ \end{tabular} & \
\begin{tabular}{c} **75 th Percentile of** \\ **Simulation Rainfall** \\ **(mm)** \\ \end{tabular} &
\begin{tabular}{c} **Seasonal** \\ **Forecast A/N/B** \\ \end{tabular} & **Hit/Miss** \\ \hline \multirow{3}{*}{1 st} & Jan. & 272.0 & 31.0 & 83.2 & 10/60/30 \\  & Feb. & 98.5 & 99.9 & 218.8 & 10/60/30 \\  & Mar. & 54.0 & 119.9 & 166.4 & 10/60/30 \\ \hline \multirow{3}{*}{2 nd} & Total & 424.5 & 250.8 & 468.4 & \multirow{3}{*}{2 nd} \\  & Feb. & 98.5 & 78.9 & 180.7 & 10/50/40 \\  & Mar. & 54.0 & 93.0 & 235.7 & 20/60/20 \\  & Apr. & 54.0 & 161.2 & 217.7 & 30/50/20 \\ \hline \multirow{3}{*}{3 rd} & Total & 206.5 & 333.1 & 634.1 & \multirow{3}{*}{3 rd} \\  & Mar. & 54.0 & 104.0 & 139.8 & 20/60/20 \\  & Apr. & 54.0 & 129.3 & 238.1 & 30/50/20 \\  & May & 49.0 & 195.3 & 313.1 & 30/50/20 \\ \hline \multirow{3}{*}{4 th} & Total & 157.0 & 428.6 & 691 & \multirow{3}{*}{3 rd} \\  & Apr. & 54.0 & 87.7 & 108.1 & 20/50/30 \\  & May & 49.0 & 209.7 & 355.3 & 20/50/30 \\  & Jun. & 113.0 & 325.7 & 335.4 & 30/50/20 \\ \hline \multirow{3}{*}{5 th} & Total & 216.0 & 623.1 & 798.8 & \multirow{3}{*}{3 rd} \\  & May & 49.0 & 262.1 & 346.0 & 10/50/40 \\  & Jun. & 113.0 & 147.3 & 180.3 & 20/50/30 \\  & Jul. & 69.0 & 135.7 & 156.3 & 20/50/30 \\ \hline \multirow{3}{*}{6 th} & Total & 231.0 & 545.1 & 682.6 & \multirow{3}{*}{3 rd} \\  & Jun. & 113.0 & 123.1 & 234.5 & 20/50/30 \\  & Jul. & 69.0 & 58.9 & 138.6 & 20/50/30 \\  & Aug. & 251.0 & 240.2 & 280.2 & 20/50/30 \\ \hline \multirow{3}{*}{7 th} & Total & 433.0 & 422.2 & 653.3 & \multirow{3}{*}{2 nd} \\  & Jul. & 69.0 & 116.7 & 147.1 & 30/50/20 \\  & Aug. & 251.0 & 157.0 & 176.5 & 20/50/30 \\  & Sep. & 202.5 & 111.9 & 220.4 & 20/50/30 \\ \hline \multirow{3}{*}{8 th} & Total & 522.5 & 385.6 & 544 & \multirow{3}{*}{2 nd} \\  & Aug. & 251.0 & 144.8 & 212.6 & 20/50/30 \\  & Sep. & 202.5 & 113.7 & 134.1 & 20/50/30 \\  & Oct. & 54.0 & 64.3 & 115.9 & 20/50/30 \\ \hline \multirow{3}{*}{9 th} & Total & 507.5 & 322.8 & 462.6 & \multirow{3}{*}{3 rd} \\  & Sep. & 202.5 & 103.7 & 197.0 & 20/50/30 \\  & Oct. & 54.0 & 79.4 & 99.2 & 10/60/30 \\  & Nov. & 42.0 & 23.0 & 50.2 & 20/50/30 \\ \hline \multirow{3}{*}{10 th} & Total & 298.5 & 206.1 & 346.4 & \multirow{3}{*}{Hit} \\ \cline{1-1} \cline{3-5}  & Oct. & 54.0 & 62.5 & 75.8 & 10/60/30 \\ \cline{1-1} \cline{3-5}  & Nov. & 42.0 & 37.4 & 62.5 & 10/50/40 \\ \cline{1-1} \cline{3-5}  & Dec. & 36.0 & 40.9 & 64.3 & 20/60/20 \\ \hline \multirow{3}{*}{Total} & Total & 132.0 & 140.8 & 202.6 & \multirow{3}{*}{Miss} \\ \cline{1-1} \cline{3-5}  & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \end{tabular}
\end{table} 
Table 4: Ten sets of seasonal rainfall outlooks and real rainfall occurrences of Xinpu station in 2018.  
was within the range of 25 th and 75 th percentiles (1193-1852 mm). In addition, according to the result of Tables 3 and 4, the results of seasonal outlook overestimated the rainfall from February to May but not January in both of these gauges. The overestimation presented in the amount of actual rainfall was less than that of the 25 th percentile of WGEN rainfall productions. This shows that the seasonal rainfall outlook easily overestimated the real rainfall during the dry season (November to April in Taiwan). Note that the amount of annual rainfall was within the range of 25 th and 75 th percentiles, although there were some missed seasonal forecasts as mentioned above.