Oxygen isotopes, major and minor chemical compositions of 23 groundwater and 5 river water samples from the southern part of Nanto City were analyzed. From these results, the possibility of groundwater heat utilization was discussed. The water temperatures fluctuated between summer and winter. The groundwater in this area nearby Sho River is strongly influenced by river water infiltration and most groundwater in other areas is considered to be derived from precipitation. The Ca²⁺, HCO₃⁻, and SiO₂ concentrations increase due to reactions with rocks during water flow from the surrounding mountains to the alluvial fan areas. In some areas, Fe scale (goethite) is assumed to be precipitated from groundwater in heat exchangers and water pipes. Based on these results, an area around Sakuragaike potentially suitable for utilization of groundwater heat was selected for study.

分析了南投市南部的23个地下水样品和5个河水样品的氧同位素，主要和次要化学成分。从这些结果，讨论了地下水热利用的可能性。夏季和冬季之间的水温波动。昭河附近的该地区的地下水受到河水渗透的强烈影响，其他地区的大多数地下水被认为是降水产生的。钙²⁺，HCO ₃ ^-和SiO ₂当水从周围的山脉流向冲积扇区域时，由于岩石的反应，浓度增加。在某些地区，假定铁垢（针铁矿）是从热交换器和水管中的地下水中沉淀出来的。根据这些结果，选择了Sakuragaike附近可能适合利用地下水热量的区域进行研究。