| 摘要: | 溫泉的水位、水溫與水質可能隨著降雨，淺層地下水的混入，不同的季節或抽取型態的差異，會產生短期或長期的變化，為了了解當地的溫泉生成概況，設置監測井進行長期監測，建立監測資料及科學數據，以提供溫泉資源管理的參考，達到資源永續利用之目的。本研究以北投的4口監測井置入儀器觀測其水溫與水位之變化，探討降雨量、水位、水溫之間的關係。雨量的數據來自中央氣象局，本研究以電腦程式自動辨別降雨事件，統計累積雨量，再以人工方式，找出相對應時期之水位水溫升降量，最後定量解釋雨量、水位、水溫之關係。研究顯示104年降雨事件總計有58次，累積雨量大於350mm有3次，而這3次的累積雨量都與颱風來襲有關，且集中在7、8、9這三個月份，明顯有旱、雨季之差別。降雨量與水位上升有明顯正相關，除BT-MW-12號監測井例外，蓋因BT-MW-12號監測井為自流井，且監測井未密封所致。發現除了少數降雨事件以外，在各場次降雨的同一天，溫泉水位歷線開始上升，並於降雨後數天內上升到峰頂，然後開始下降，尤其是累積降雨量大於200mm，可讓水位線維持一段時間，明確顯示降雨與補注之因果關係。降雨量與水溫，BT-MW-12號監測井與BT-MW-13號監測井呈現無相關，推估原因是因降雨流入地面，因監測井溫泉含水層和地面水或和淺層土壤水的連通性不好，造成監測井水溫變化與降雨呈現無相關。BT-MW-14號監測井呈現負相關，推估原因是因降雨流入地面，因BT-MW-14號監測井溫泉含水層和地面水或和淺層土壤水的連通性極佳，造成冷水流入，因此溫度下降。降雨量與水溫，BT-MW-16號監測井呈現正相關，推估原因是因遠處降雨流入地面下，冷水經過深循環，地底下有熱源造成水溫上升；抑或因地溫梯度，水流經地底下，隨深度溫度上升等原因造成。
The variation of hot spring’s water level, quality and temperature were relative with the precipitation, ground water. For the sustainable use and better management of the hot-water resource, a water pressure and temperature monitoring program is set up to establish monitoring data.In this study, we placed some instruments into four monitoring well in Beitou Hot Spring area and to observe the change of water level and temperature and finally understand the relations among rainfall, water level and water temperature. We obtained the rainfall data from the Central Weather Bureau, and then identified the rainfall events automatically with computer programs. In the end, we added up the accumulated rainfall, and then manually researched the change of the water level and water temperature at the corresponding period.This study displays there have been fifty-eight rainfall events in the year of 2015, three of them with cumulated precipitation of more than 350 mm, which are related to typhoons and concentrated in July, August and September. It shows obviously the difference between dry and rainy seasons. By the recorded data, there is significantly a positive correlation between precipitation and the rate of water level rising, with the exelusion of the monitoring well No. BT-MW-12, which is an unsealed artesian well. It was found that except for a minority of the rainfall events, the hot spring water level hydrograph started to rise at each of them on the same day. Moreover, after several days of the rainfall, the water level rose to the peak, and then started to decline, especially when the accumated rainfall was more than 200 mm. This allowed the water level to maintain at a certain place for a while, which clearly shows the causal relationship between rainfall and recharge.Nevertheless, there is no correlation between rainfall and temperature in the monitoring wells No. BT-MW-12 and BT-MW-13. We have the inference that it is contributed to the rainfall seepage into the ground, which is caused by the bad water permeability of the aquifer, the surface water and the shallow soil of these two monitoring wells. A negative relationship between rainfall and temperature in monitoring well No. BT-MW-14 should be contributed to the good water permeability. Hence, the cold water is allowed to flow into the area and this makes the temperature drop. On the contrary, there is a positive correlation between rainfall and temperature in the monitoring well No. BT-MW-16. We suggest that it is resulted from the inflow of rainfall in the distance, the deep circulation of cold water and the hot-water resource underground which leads to evelate the temperature. Moreover, It is likely influenced by the geothermal gradient, the underground inflow of water and the rising depth temperature. |
