The Investigation of Groundwater Hydrological Variations Triggered by Earthquakes in Chianan-Kuoping Areas

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.