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年度	109	專案性質	實驗性質
專案類別	模場試驗	研究主題	調查
申請機構	國立臺灣海洋大學	申請系所	地球科學研究所
專案主持人	邱永嘉	職等/職稱	副教授
專案中文名稱	分散式光纖溫度感測器在地下水污染場址之高解析度井下水文地質調查
中文關鍵字	分散式光纖溫度感測器、熱示蹤劑、地下水污染、加熱控制系統、水文地質
專案英文名稱	Using fiber optic distributed temperature sensor as a downhole tool to investigate the hydrogeology with high resolution
英文關鍵字	fiber optic distributed temperature sensor, heat tracer, groundwater contaminated site, heating pulse controller, hydrogeology
執行金額
執行期間	2020/1/30 至 2020/12/4
計畫中文摘要	本研究為兩年期模場試驗專案，以分散式光纖溫度感測器(fiber optic distributed temperature sensor, FO-DTS)於地下水污染廠址進行高解析度水文地質調查。第一年度執行項目為針對監測井進行熱水注入試驗，藉由溫度回升的過程可判釋不同深度之透水性，並以耦合地下水數值模式MODFLOW與MT3DMS模擬停止注水後溫度回復之過程，針對水文地質參數進行量化。第二年度執行項目為以主動式加熱法針對監測井進行加熱試驗，透過升溫和回復的過程判釋井下不同深度之透水區段，並以線性熱源之熱傳輸解析解分析溫度量測資料，進而推估不同深度之地下水流速。研究區域主要以廠區內地下水上游的井E-01與周圍監測井E-01-1與E-01-2為主，地下水下游的監測井則僅進行溫度變化監測。研究結果顯示，上游監測井之透水區段主要分佈在深度7~10公尺，不透水區段為12~14公尺，下游監測井在加熱期間亦可接收到些微溫度上升之訊號。以耦合數值模式所計算之水平向水力傳導係數與熱傳輸解析解量化溫度資料後所推估之地下水流速結果相符合。由於FO-DTS可提供時、空中的高解析度連續性量測資料，在分析井下不同深度之地下水流速分佈時，其空間中的解析度可高達50公分；由於光纖佈設成本相對較低，不僅可同時針對多口監測井進行試驗，亦可於短時間進行多次量測，提供水文地質環境隨時間之演變。透過解析解針對加熱時間與地下水流速進行敏感度分析，可更進一步提供FO-DTS搭配加熱系統在量測作業上之標準流程。本專案計畫提供之FO-DTS創新量測技術可在不擾動地下水流的情況下有效進行井下高解析度水文地質調查，避免污染物因注水或其它外力而造成污染範圍擴大，本計劃之研究成果可提供污染場址調查與整治上之重要評估與參考依據，藉由此創新量測技術的研發，未來可大幅度提升我國在水文地質調查的解析能力。
計畫英文摘要	This study is a two-year in-situ project. The fiber optic distributed temperature sensor (FO-DTS) is applied in a groundwater contaminated sites to investigate hydrogeological conditions. The injection of hot water into the wells were conducted in the first year. The permeable zone at different depths can be identified via temperature recovery. Besides, the hydrogeological parameters can be estimated by the coupled numerical models of MODFLOW and MT3DMS which are used to simulate the process of heat transfer. In the second year, the active-DTS is applied to estimate the groundwater flow velocities at differet depths. The permeable zone at different depths can be identified via the temperature rising and recovery. Besides, the groundwater flow velocity is quantified by the analytical solution of heat transfer with a heated line source. This study area mainly focused on three wells at the upstream of groundwater flow direction, i.e., E-01, E-01-1 and E-01-2 and the rest of wells at the downstream of were used for monitoring. The results show that the distributions of high and low permeable zones are at the depth of 7~10m and 12~14m, respectivity. The temperature changes were observed in the wells at the downstream. Compared to the hydraulic conductivities obtained from the coupled numerical models, the estimated flow velocities through the analytical solution are consistent with each other. Due to continuous measurments of DO-DTS, the spatial resolution of estimated flow at different depths can reach to 50 cm. The low cost of fiber optic cable makes it is feasible to conducte many field tests within a short period of time and provides further information of changes of hydrogeological environment. Furthermore, the analysis of using the analytical solution can provide the sensitivity between the heating time and temperature changes and establish a standard operating procedure for the FO-DTS test. In this study, the innovative FO-DTS can provide an alterntive technique of hydrogeological investigation effectively without disturbing groundwater flow and extending the contaminated plume. The developed technique and measured procedure can be considered as a reference tool and improve our capability of hydrogeological site investigation and groundwater contaminated sites remediation.