Model Development for Su-Ao Cold Springs and Analysis of Groundwater Level and Temperature Change

台灣蘇澳冷泉早在日治時期即做為泡澡使用外，更曾被開發作為氣泡水。到了民國74年陸續規劃各式浴池並建闢觀光遊憩區，近年來更有數次調查研究，並持續監測水位水溫變化以期長期經營利用。蘇澳冷泉因其泉水中富含游離二氧化碳，浸泡冷泉有助於人體心血管的循環，且因全年維持22℃的特性，除了冬天適合浸泡外，夏天也因涼爽的溫度而比溫泉更能吸引遊客前來。 然而隨著冷泉區的蓬勃發展，我們需要注意抽用過度的問題。本研究探討蘇澳冷泉區域地降雨入滲對於水位水溫的影響，以及分析不同抽水比例對於水位與水溫的影響，並以永續經營觀點從中推估合理抽水量。研究中先以SWAT模式來模擬有效入滲量，藉由土地利用、土壤地質、地表高程、河川水系與氣象資料輸入模式內求得有效入滲量後，配合水文地質與熱傳參數作為SHEMAT模式的參數設定值，並在模型上加入可能破裂帶位置、抽水及自湧位置、邊界與初始條件後，模擬溫泉水位及水溫之變化。 模式模擬結果之校正與驗證以經濟部水利署台灣溫泉監測季報中蘇澳冷泉2013年至2014年水位水溫觀測值作為比較分析之依據。入滲之自湧量校正值趨勢與降雨入滲趨勢相符，而水位水溫模擬結果以未抽水使用的溝邊井最為良好，冷泉公園井次之，瓏山林則受到模擬深度以外之深層抽水井影響僅在趨勢變化上符合。另調整抽水量對水位水溫之影響分析，可發現抽水比例增加皆會降低三口監測井水位及水溫，而藉由希爾法分析本研究認為合理抽水量應為1409 CMD，然分析上僅考量2013年的抽水量評估，對於不同年份有其不確定性存在。最後本研究分析有無入滲對於水位與水溫的變化，在有入滲情況下，於冬季豐水期時可提高水位0.8至1.1公尺；夏季時則提高0.13至0.4公尺。至於水溫部分在有入滲情況下會使得溫度降低，冷泉公園井平均約降0.016℃、溝邊井降0.006℃、瓏山林井降0.007℃。Only few countries exist resource of cold spring, and Taiwan is one of them. In Taiwan, Su-Ao Cold Spring, which locating in Su-Ao town in Yilan County, had been developed as not only the bath use, but only the sparkling water during the Japanese-Occupied Period. After 1985, it has been planned to build various types of baths and tourist recreation area. And in recent year, there are several researches about Su-Ao Cold Spring, and monitor the groundwater level and temperature. Because the cold spring dissolves much carbon dioxide, soaking in the cold spring has good benefit for cardiovascular circulation. Moreover, it suit for soaking all the year, especially in summer because the temperature of spring keeps 22℃ throughout the year. However, with the development of Cold Spring area, we need to pay attention to the problem of overdraft. In this research, the impact of precipitation and pumping on groundwater level and temperature is investigated. This research also analyzes different pumping quantity to observe the change of level and temperature. SWAT is applied to simulate the effective infiltration. This step requires gathering information such as land-use, soil-geology, surface elevation, river systems and weather. The effective infiltration then serves as input in SHEMAT. Along with setting hydrogeology and thermal parameters, the position of fractures, and the boundary and initial conditions, SHEMAT can simulate the change of water level and temperature. In this research, the observation groundwater level and temperature got from the hot spring quarterly report of Taiwan is used for model Calibration and validation. The result shows that the Go-Biang well has the best simulating result between three monitoring well because it is not a pumping well. However, the RSL well has the worst simulating result between three monitoring well. The worse result for RSL well is considered that the influence of deeper pumping well. The amount of correction of lateral recharge and spring relate to the rainfall trend. Another analysis in this research is changing the amount of pumping to analyze the impact of groundwater level and temperature. The result shows that increasing pumping quantity will decrease the groundwater level and temperature. The rational pumping quantity is 1409 tons / day which is higher than the currently pumping quantity, but lower than the maximum pumping quantity limited by government. Finally, this research analyzed the impact of infiltration for the groundwater level and temperature. In the normal condition which input infiltration in model, the groundwater level raise 0.8 to 1.1 meters during the winter, and 0.13 to 0.4 meters during the summer because of the infiltration. Moreover, the groundwater temperature average raise 0.016 ℃ at cold spring park well, 0.006 ℃ at Go-Biang well, and 0.007 ℃ at RSL well without the infiltration