嘉南高屏地區地震引致地下水文特性變化研究(II)

The mechanism of earthquakes induced groundwater hydrologic anomalies have been widely investigated and discussed in the world in the recent decades. The high density of observation wells and strong motion stations in Taiwan not only provide the information for 2D distribution but also at different depths in the vertical direction. Taiwan is one of the most suitable sites in the world for the study of earthquake hydrology. Meinong earthquake took place in 2016 has an abnormal damage in the area with 30 km away from epicenter. The area with strong earthquake intensity also located in the faraway area not close to that near epicenter. Therefore, Meinong earthquake is a good event to validate the mechanisms proposed to explain the earthquake induced groundwater anomalies. Our previous study thus focused on integrating different observation data to analyze the groundwater anomalies induced by Meinong earthquake. Some valuable observations and mechanisms have been proposed and a anuscript was written and submitted to a high impact journal for the possible publication. The results show different points of view corresponding to the previous studies, especially not match the concepts of epicenter distance and relative mechanics. Some results support other mechanisms proposed in the other researches. However, only one earthquake event is not sufficient to fully support the proposed mechanism in our previous study. Therefore, this following study selects the 2010 Jiashian earthquake with similar earthquake magnitude and nearby epicenter for the comparison. Similar study processes will be conducted to analyze the collected data and validated the proposed mechanisms with the results of Jiashian earthquake. In addition, tidal analysis and volume strain sensitivity analysis will be included in this study to estimate the variations of hydrogeological property induced by earthquakes. The results are used to validate the suitability of the commonly used mechanism, permeability enhancement, for the earthquake hydrology. This study will also discuss the mechanism of soil liquefaction, similar to groundwater variations, and estimate the possible improvement of the assessment of soil liquefaction potential. This study would like to provide the information of changing characteristics of aquifer system induced by earthquakes through the analyses of the integrated observation data. The results can provide the reference of groundwater resource and earthquake relative issue.