高雄美濃地震引起地下水文變化現象之機制，目前尚未有完整的探討，亦未納入其他資料進行進一步的分析與研究；鄰近地區較大地震事件引致水文異常變化亦尚未有詳細比較與討論；而地下水高頻觀測站也尚未針對台灣地區的地震事件進行水文統計與空間敏感度分析。因此，本研究研提三年期計畫，將以嘉南高屏地區地震引致地下水文變化資料為基礎，配合降雨量與河川流量等相關水文資料，進行地震水文資訊分析；並與其他不同觀測資料之研究結果進行交叉比對，以探究地震事件對地下水文系統的影響機制。第一年將以高雄美濃地震為案例，進行水文異常分析與應力區計算，建立分析方法與架構，並於高頻地下水位站建立震波觀測儀器；第二年將增加蒐集甲仙與霧台地震事件資料，進行分析、比較與探討，採用地潮分析方法了解不同地震事件對水力特性之影響，採用體積應變敏感度結果改善土壤液化潛勢評估之準確性；第三年將以高頻觀測井對全台近十年地震事件之反應，進行水文統計分析與空間敏感度分析，並對第一年設置觀測系統蒐集資料做分析，了解震波對地下水位變化之影響機制。本計畫期望透過地震引起水文變化之觀測資料，來瞭解含水層系統的特性，提供未來地下水資源與地震相關研究之基礎。 ;The mechanisms for some phenomena of groundwater level variations due to the Kaohsiung Meinong Earthquake are not yet clearly investigated. The observations data in different fields for that earthquake are not completely compared with the hydrology information. Groundwater anomalies due to the vicinal earthquakes in Chianan-Kaoping area also did not be compared and discussed to realize the possible mechanism. Besides, the hydrology analyses and spatial sensitivity of the observation wells with high sampling frequency to response the Taiwan earthquakes have not been fully analyzed. Therefore, this proposal proposed a three-year project to investigate the mechanism of earthquake hydrology triggered by earthquakes in Chianan-Kaoping area. The earthquakes and hydrology data will be collected and analyzed to realize the fundamental information and confirm the accuracy of data. In the first year, groundwater level anomalies will be classified and analyzed to illustrate the spatial distribution, and compared with other observations induced by the Kaohsiung Meinong Earthquake to investigate the possible mechanism of the observed phenomena. Six seismometers will be installed near the wells with high sampling frequency to observe the seismicity for comparison. In the second year, similar earthquakes (Jiaxian and Wutai earthquakes) with groundwater level observations will be collected and analyzed to compare with those of Meinong earthquake. Earth tide analysis will be used to assess the variations of hydraulic properties due to different earthquakes. Volumetric sensitivity analysis will be used to assess the groundwater pressure under seismicity which can be used to improve the assessment of liquefaction potential. In the third year, the spatial sensitivity of the wells with high sampling frequency will be conducted by using the indicator kriging method. The collected groundwater level and seismicity data from the installed devices will be analyzed to confirm the mechanism of groundwater level anomalies. The results of this project will provide the possible mechanisms for the phenomena of groundwater hydrology in the Kaohsiung Meinong and other similar earthquakes in Chianan-Kaoping area. The results can also provide the fundamental information for groundwater resources and earthquake investigations.
