Abstract Water level and hydrochemical parameters from groundwater monitoring wells can be effectively used for interpreting changes in the groundwater system when aquifers are appropriately characterized. Groundwater levels in six paired monitoring wells of alluvial and sedimentary bedrock aquifers in the Gyeongju area, southeastern South Korea were analyzed to evaluate their abrupt changes due to earthquakes, and to identify the differences in responses of groundwater level to the earthquakes and precipitation based on confining conditions of the aquifers, which was verified by principal component analysis (PCA) of water level and major ion concentrations, and lithologic logs. When earthquakes occurred in 2016 near the study area, the different responses of groundwater level to the earthquakes were detected in the two well pairs under confined condition. In particular, wells with single screened interval showed dissimilar patterns in water level fluctuation and hydrochemical water type. The PCA results of groundwater levels and hydrochemical parameters also substantiated the different aquifer types in the two well pairs. These results suggest that groundwater monitoring data should be acquired and analyzed considering the well design and aquifer type to properly evaluate impacts of earthquakes on the aquifers, which can contribute to establishment of earthquake monitoring systems.

中文翻译：

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利用冲积和沉积基岩含水层地下水监测数据的时间变化评估含水层对地震的响应

摘要 当含水层被适当地表征时，来自地下水监测井的水位和水化学参数可以有效地用于解释地下水系统的变化。分析了韩国东南部庆州地区冲积和沉积基岩含水层的 6 个成对监测井的地下水位，以评估其因地震引起的突变，并确定地下水位对地震和降水响应的差异。含水层的条件，通过水位和主要离子浓度的主成分分析 (PCA) 和岩性测井来验证。2016 年研究区附近发生地震时，在封闭条件下，在两个井对中检测到地下水位对地震的不同响应。尤其是单层筛选井在水位波动和水化学水类型方面表现出不同的模式。地下水位和水化学参数的 PCA 结果也证实了两个井对中不同的含水层类型。这些结果表明，应考虑井设计和含水层类型来获取和分析地下水监测数据，以正确评估地震对含水层的影响，这有助于建立地震监测系统。地下水位和水化学参数的 PCA 结果也证实了两个井对中不同的含水层类型。这些结果表明，应考虑井设计和含水层类型来获取和分析地下水监测数据，以正确评估地震对含水层的影响，这有助于建立地震监测系统。地下水位和水化学参数的 PCA 结果也证实了两个井对中不同的含水层类型。这些结果表明，应考虑井设计和含水层类型来获取和分析地下水监测数据，以正确评估地震对含水层的影响，这有助于建立地震监测系统。