## 4 Results
### Hydrological Elements  
The model outcomes were employed to scrutinize the intra-annual fluctuations of major hydrological constituents within the basin (refer to Figure 7). The findings reveal that variations in hydrological components--comprising surface runoff, lateral flow recharge to runoff, and groundwater recharge to runoff--generally mirror the oscillations in precipitation. When precipitation peaked in April, July, and October, these hydrological components also peaked in those months. The largest increase in precipitation was 449% in June compared to May. During this period, surface runoff, lateral flow recharge to runoff, and groundwater recharge to runoff increased by 828%, 371%, and 287%, respectively. The largest decrease in precipitation was a \(-\)95% change from November to October. The surface runoff, lateral flow recharge to runoff, and groundwater recharge to runoff changed by \(-\)95%, \(-\)89%, and \(-\)72%, respectively. The magnitude of change in these hydrological \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Index**} & \multicolumn{2}{c}{**Fuzhong Station**} & \multicolumn{2}{c}{**Shanshou Station**} \\ \cline{2-5}  & **Calibration** & **Validation** & **Calibration** & **Validation** \\ \hline R\({}^{2}\) & 0.64 & 0.61 & 0.65 & 0.56 \\ NSE & 0.61 & 0.59 & 0.64 & 0.57 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Evaluation of hourly flow simulation results at Fuzhong Station and Shanshou Station. Figure 6: Comparison of simulated and observed hourly flows at Fuzhong Station (**a**) and Shanshou Station (**b**). components differed from the magnitude of change in precipitation, but the trend of change (increase or decrease) was consistent. However, noteworthy temporal disparities emerge, with groundwater changes lagging behind shifts in surface runoff and lateral flow recharge to runoff. Groundwater recharging rivers encounters obstacles, such as rocks, soils, and other geologic materials, that cause it to flow at a slower rate. The sluggish response of groundwater may be related to local geologic and topographic conditions. Even though November's precipitation falls below 15 mm, groundwater recharge to runoff registers at 20 mm. Due to the fact that in October, the precipitation reached a maximum of 295.7 mm among all the months of the year, a large amount of water was stored under the rocks as groundwater through soil infiltration, which was partly recharged to the runoff in the same month and partly flowed out in the following November due to the slow recharge of the groundwater. Furthermore, during months with equivalent precipitation (such as June and September), the recharge values of lateral flow and groundwater contributing to runoff were higher in September than in June. This difference can be attributed to the substantial summer precipitation (occurring in June, July, and August) being stored in aquifers, soil, and vegetation, which was subsequently released in September. Most of the rocks in the basin are igneous rocks (Figure 2), which are one of the hardest rocks, characterized by fewer unbreakable pores. The extensive prevalence of these rocks in the basin establishes favorable geological conditions for groundwater storage while simultaneously decelerating the rate of groundwater recharge. Furthermore, the watershed is predominantly covered by forests. During months with high precipitation, the trees' roots, stems, and leaves have the capacity to store excess rainfall and gradually release it during dry periods. This process effectively maintains soil moisture content and enhances river runoff. Cumulatively, across the entire year, basin-wide contributions from surface runoff, lateral flow to recharge, and groundwater to recharge represent 27.3 mm, 483.2 mm, and 205.0 mm, respectively. These figures correspond to 2%, 43%, and 18% of the total precipitation. The substantial presence of flow in the soil and groundwater suggests that water resources in this region easily infiltrate.