本計畫試圖在大屯火山區域之地下水井的水溫與水之氫氧同位素來回答水在安山岩山 區之岩石水層中的循環機制並建立區域地下水的流動模式。氫氧同位素長久以來都是建 立流域中降雨-逕流之關係中的有效利器，但是基岩對地下水的影響，尤其是安山岩地 區的研究相對較少。大屯火山群位於台灣北部，在大屯火山底下可能存在的岩漿庫，異 常溫度下的岩石與水之間的交互作用或許可作為另一種對區域地下水的流動模式了解 的方式。我們將利用在七星山北邊五口鄰近金山斷層之溫泉監測井，透過連續密集在這 一小流域中對地下水、地表水之採樣，並利用溴追蹤劑來探討地下水在區域基岩中的行 為機制。近年來，地下水研究已逐漸體認到地下水在未固結沉積物中的行為並不能完全 適用於固結的岩層中而且在岩石水層中這問題更顯得複雜。本研究區域位於大台北都會 區附近而且最近研究顯示本區域岩漿庫存在的可能性，因此本計畫的結果可以對安山火 山區域地下水之循環作用的進一步了解，也能提供溫泉水資源的重要訊息更希望能提供 大屯火山監測相關之資訊 本校具有地利之便，加上本系已建置一套水氣氧同位素儀器（Picarro Isotopic Water Liquid Gas Analyzer L1102-i）以及四組地下水微量追蹤量測器(Temphion Submersible Smart pH/ISE/Redox Sensor)，其中溴的解析度可達 0.01ppm。我們希望透過密集量測 在不同地質岩層中地下水、溪水、以及泉水中之δ18O 與δD值並同時在井下施放追蹤劑來 進一步瞭解地下水在安山岩區的循環機制行為與地下水流動模式，並利用本計劃的機會 提供研究生與大學生對地科環境的訓練，而且也希望本研究的結果能提供有效的訊息給 予大屯火山監測之用。 Two commonly addressed questions in hydrogeologic investigations are (1). where does water come from (where is the source, or recharge area for groundwater)?(2). where does water go (what is the depth and lateral extent of the groundwater circulation)? This is particular crucial to the bedrock regions where exhibit a very wide range of hydrogeological characteristics and circumstances. There has been an increasing awareness that in many circumstances the theories associated with the description of hydrogeologic processes in granular porous media are unadoptable completely in the description of these same phenomena in fractured rock and geologic formations. This discrepancy phenomenon makes the research in hardrock hydrogeology so valuable than ever, particular in Taiwan because that most researches efforts have been made in unconsolidated media for the past 20 years in Taiwan. We are proposing an interdisciplinary study in groundwater study by analyzing isotopes in surface and subsurface waters, conducting tracer test and chemical analysis in 5 monitoring wells nearby the JinShan Fault, an active fault in the north Taiwan to attempt to identify and delineate the regional groundwater flow pattern by measuring δ18O and δD and water levels. We are well equipped and pose several advantages for proposing this project. First, we newly purchased 4 sets of tracer test equipment (TempHion Submersible Smart pH/ISE/Redox Sensor)with a well-function isotope analyzer for both liquid and gas phase( Picarro Isotopic Water Liquid Gas Analyzer L1102-I). This enables us to complete the study right in our department and to determine how the bedrock groundwater process in the study area. Secondly, we are located right in the Tatun Volcano Group(TVG); it allows us to sample effectively whenever it necessary. We hope this project will serve as a platform for training students on sampling and measurements skill in hydrogeological parameters.
