| Summary: | 碩士 === 國立中央大學 === 應用地質研究所 === 107 === Hyporheic zone locates in the interaction area between surface water and groundwater. Hyporheic flow in this zone is one of the relatively stable water resources that is storing in the gravel layer below the river channel and has the advantage of great water quality. The potential and effective management of water resources in hyporheic zones are important issues for regional water resource assessments. The study aims to integrate index overlay and numerical methods to assess the potential of hyporheic water resources in groundwater basins of Taiwan. In this study, the Kriging module in ArcGIS and GOD (Groundwater occurrence rating, Overlying lithology rating, and Depth to water rating) method for potential assessments are employed to conduct the interpretation of the hyporheic water resource potential. The factors in GOD includes the transmissivity, slope, difference between groundwater and river levels (Delta H), drainage-length density, and depth to groundwater. The comparison of the analytical solution and HYDRUS numerical simulation is conducted based on the data taken from the engineering-scale site on the Qingshui River. The study considers Lanyang and Pingdong plains to be the selected groundwater basins for quantifying the available water resource from hyporheic flows. The study assumes that the influence of water intake facilities can be neglected with a distance of 1 km from two facilities. Based on the existing water intake facilities in Lanyang and Gaoping rivers, including Lodong weir, Gaoping riverside dike, Jhuliao water-pumping station, Jiuqutang water-pumping station, and Huijie water station, the total discharge of hyporheic flow are calculated for different rivers. The index overlay method shows that the Lanyang Plain is the highest potential area of the hyporheic flow. However, Taoyuan tableland is the lowest potential area of the hyporheic flow. The designed water intake estimated by numerical simulation is about 1.1 to 1.4 times higher than that obtained from the analytical solution. This study estimated water resource of hyporheic flows in Lanyang River in Lanyang plain is from 6.54 million CMD to 9.10 million CMD (Cubic meter per day). Based on the design of the water intake facilities along the Gaoping River, the water resource of hyporheic flows along the Gaoping river in Pingtung Plain is about 2.53 million CMD to 6.23 million CMD.
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