圖書典藏及影音數位平台

依98年度辦理之「地下水補注機制水力特性調查分析先驅研究」計畫初步成果，水井水力斷層掃描已完成現地小尺度井場試驗並利用水力斷層掃描概念完成水力參數異質性分析，驗證水力斷層掃描理論應用於現地抽水試驗之可行性；此外河川水力掃描亦於先期研究中，完成初步河川水位與地下水位相關性分析，並初步驗證河川水力掃描應用於中尺度水力斷層掃描之可行性。然此二項研究工作於應用於現有地下水觀測網，亦即流域或沖積扇尺度之水力參數異質性分析之可行性，仍待充份確認，故本計畫擬以沖積扇尺度範圍為研究對象，以前開二項先進分析技術結合現行地下水觀測網水位觀測資訊，檢定異質性水力參數特性。

Abstract Controlling of aquifer hydraulic parameters is the main factor influencing the future groundwater resources management and recharge evaluation. However, the hydraulic parameters can only be obtained from few wells which have been implemented water tests or from models calibration, existing hydraulic parameters were used to acquire parameters of other areas by kriging method. There are several differences between hydraulic parameters obtained from the method stated above and from in-situ tests. In order to improve the accuracy of hydraulic parameters, the project cited advanced hydraulic tomography and river stage tomography technologies from foreign counties and operated in coordination with the monitoring function of present groundwater observed wells network to apply to Chou-shui river alluvial fan. In order to improve the accuracy of hydraulic characteristics estimation, and plan future development of hydraulic tomography and river stage tomography technologies, the project estimated data by hydraulic tomography and river stage tomography using numerical simulation methods which considering the hydraulic parameters obtained from the large-scale pumping tests, determining observation wells which had high correlation among groundwater levels, and considering correlation between river water level and groundwater level changes. The results of the project are: (1) hydraulic conductivity of aquifer one to four estimated by hydraulic tomography using artificial pumping behaviors are the same with the actual situation, therefore, using current artificial pumping behaviors to estimate hydraulic conductivity of a large-scale aquifer is feasible, (2) according to the results of correlation analysis between river stage and groundwater level, correlation coefficient distribution are similar in upstream, middle stream and downstream of Chou-shui river, and there are high correlation between river stage and groundwater level in southeast and northwest alluvial fan of Chou-shui river, (3) the influence of Chou-shui river and Beigang river on the groundwater level of this area are the similar, (4) according to the results of groundwater recharges potential, high potential recharge regions are along the Chou-shui river, (5) average yearly recharge depth of Tu-ku bridge watershed and Beigang(2) watershed are 87.4cm and 65.06cm respectively, (6) leakage of soil layers is decreasing in Chou-shui river alluvial fan from upstream to downstream. Keyword: hydraulic tomography, river stage tomography, correlation analysis, groundwater

本計畫旨在提升濁水溪沖積扇地下水資源管理與補注評估的準確性，因現有水力參數掌握不足且多假設均質，故引進國外先進的「水井水力斷層掃描」及「河川水力掃描」技術。透過大型抽水試驗、數值模擬及河川與地下水位相關性分析，以精確掌握濁水溪沖積扇的水力參數特性。 研究成果顯示： 1. 以人為抽水行為進行大範圍水力斷層掃描推估水力傳導係數是可行的，且與實際情況相符。 2. 濁水溪各河川水位與地下水位變化有顯著相關性，尤其在沖積扇東南及西北角隅處相關性更高。 3. 濁水溪與北港溪對該區域地下水影響程度相當。 4. 濁水溪沿線因砂、礫石層與農地分佈，入滲能力優越，具有極佳的地下水補注潛能。 這些成果有助於提高濁水溪沖積扇地質特性評估的準確性，並為未來地下水補注機制推動與發展提供重要基礎。