跳到主要內容 :::

年度	102	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	國立台灣大學	申請系所	地質科學系
專案主持人	賈儀平	職等/職稱	教授
專案中文名稱	熱脈衝流速儀應用於地下水污染場址調查之可行性研究
中文關鍵字	地下水污染；流速儀；先導試驗；場址特性
專案英文名稱	Feasibility study of the application of heat-pulse flowmeter to site characterization of groundwater pollution
英文關鍵字	groundwater pollution；flowmeter；pilot test；site characterization
執行金額
執行期間	2012/12/10 至 2013/12/9
計畫中文摘要	地下水流及污染傳輸會隨著不同的水文地質特性而改變，地下水流通常集中 於少數透水性較高的區段，因此瞭解地下水流在空間上的分布及水文地質特性是 地下水污染場址最重要的調查目標。本計畫採用熱脈衝流速儀量測水力傳導係數 在井孔中垂向分布，研發流速校正方法，改進現地量測技術，並在地下水污染場 址進行模場試驗，以瞭解此項進階技術之可行性。本研究先進行室內試驗，繼而 在台大農場和南投和社水文地質試驗井場進行現地測試，經由不同地質條件及不 同試驗方式之經驗與成果，瞭解熱脈衝流速儀現地量測的過程與效能，藉此規劃 模場試驗之施作方法，並設計操作流程。台大農場試驗井建置在未固結沉積物之 含水層，同時採用抽水式及注水式流速儀試驗，試驗結果顯示該試驗井的透水性 質雖然隨地層深度而改變，兩種不同試驗方式可獲得類似的結果，然而因為抽、 注水速率的差異，造成兩者間存在誤差。南投和社水文地質試驗井場為裂隙岩體 之含水層，試驗結果顯示熱脈衝流速儀可偵測透水的裂隙，協助瞭解優勢水流路 徑。熱脈衝流速儀量測技術的模場試驗選定在中油高雄煉油廠進行，本研究在二 輕附近場地建置兩口 12 公尺深之地下水試驗井，在探測當地的地質特性後，進行 抽水式及注水式流速儀量測試驗，結果顯示當地多為中粗砂質土層，但垂向的透 水性分布相當不均，深度 8.0 至 8.25 公尺處為兩口井試驗區段中最為透水的範圍， 分層水力傳導係數達 1.306 m/min，約為水力試驗所得平均水力傳導係數的 7.6 倍。 兩口井的抽水式量測結果呈現相當類似的分布，然而目前注水速率穩度欠佳，解 析度不如預期，未來仍需持續研究改進注水技術。模場試驗結果指出熱脈衝流速 儀試驗可以量測出分層水力傳導係數，具有潛力應用於地下水污染場址調查，協 助評估地下水污染監測、污染傳輸速率、規劃污染整治、及數值模擬分析工作。
計畫英文摘要	Groundwater flow and contaminants transportation are affected by different hydrogeological conditions, therefore, it is essential to investigation of the distribution of flow paths and aquifer characteristics. This project adopted heat-pulse flowmeter measurement to delineate the vertical distribution of hydraulic conductivity in the borehole. The research developed calibration method for measured velocity and improved the field measurement techniques. A pilot test of the heat-pulse flowmeter measurement was conducted in a groundwater contamination site. The field tests were conducted in the NTU and Heshe Hydrogeological Experimental Well Station. The aquifer in the NTU is composed of unconsolidated deposits. Both the pumping-type flowmeter test and injection-type flowmeter test were implemented. The test results indicate that the hydraulic conductivity varies with depth, but similar results were obtained by two methods. However, resolution of the results from the pumping-type method is better. The Heshe Hydrogeological Experimental Well Station is located in the fractured rocks. Our heat-pulse flowmeter measurement results can locate the permeable fractures and preferential flow paths. The pilot test was conducted in the Kaohsiung Refinery of CPC. We established two wells with a depth of 12 meters. The soil samples indicate that the strata are composed primarily of sand, but the distribution of hydraulic conductivity changes significantly with depth. The most permeable zone for both wells is between the depth of 8.0 and 8.25m. The highest horizontal hydraulic conductivity is about 1.306 m/min, which is 7.6 times of the equivalent hydraulic conductivity of the whole aquifer. Besides, the injection-type test results of two wells show similar distribution of groundwater flow, indicating the feasibility of the developed technique. However, the resolution of test results from injection-type method is fair, requiring further research to improve the stability of injection rate. We think that current measurement technique of the heat-pulse flowmeter has potential in the application of characterization and remediation of groundwater pollution, particularly in the groundwater monitoring, contamination transport, remediation design and groundwater modeling.