- 期刊
屏東平原地下水重要補注區及保育區範圍評估
The Assessment of Groundwater Recharge and Conservation Area of Pintung Plain
摘要
就區域地下水的管理而言，重要補注區的評估乃是首要的課題之一，最近通過的地質法，更將重要地下水重要補注區列為需加強調查與保育的地質敏感區之一。本研究乃以因子潛勢分析，配合現地二維地電阻及水質調查等，首先評估以淺層含水層為主要考量的屏東平原重要地下水重要補注區之分布，接著分析以整體含水層為範圍的地下水保育區。因子潛勢分析部份，重要補注區的評估考量了7個因子，保育區分析則以其為基礎，增加了與深層含水層地下水蘊藏量相關的因子。前述潛勢分析成果進一步以二維地電阻及水質調查分析驗証，其中二維地電阻施測總長度達7240公尺，而水質檢測則以溶氧量為指標。分析結果顯示三種方法所推得之結果相當一致，潛勢分析所得之高補注潛勢區與二維地電阻調查結果，兩者重疊的面積達95.85%。水質檢驗亦顯示，觀測井溶氧量於高補注潛勢區內之濃度值皆相較區外明顯偏大，區內最小值為3 mg/l以上。本研究所建議之屏東平原重要補注區及重要保育區範圍，除了可作為區域地下水管理策略的重要參考外，並可作為後續劃設地質敏感區之重要依據。
並列摘要
Assessing groundwater recharge area is an important issue for regional groundwater management. The Law on Geological and Mining Activities has recently issued, groundwater recharge area becomes a part of geological sensitivity district which is required higher level survey and protection. This study uses factor analysis to assess the groundwater recharge area and conservation area. To validate the recharge area identified, 2D electrical resistivity and water quality are adopted. The total measurement length of the 2D electrical resistivity survey is 7,240 m and the water quality index is dissolved oxygen. The assessment first focuses on shallow aquifer for recharge area and then evaluates the entire groundwater aquifer for groundwater conservation area. The factor analysis adopts seven factors to identify the groundwater recharge area. After the recharge area is identified, a factor related to the storage of deep aquifer is added to determine the groundwater conservation area. The identified groundwater recharge area is compared with the results obtained from the 2D electrical resistivity survey and the water quality examination. All three methods show consistent result, which indicates that ninety-six percent of identified area is overlapped between the factor analysis and the 2D electrical resistivity survey as well as the concentration level of the dissolved oxygen in the identified area is higher than the outside area. This study proposed a methodology to identify the groundwater recharge and conservation area. The identified area provides important reference for groundwater management and designation of geologic sensitive.