Model establishment, verification and quantification of deep displacement mechanism

To understand the compaction situation caused by groundwater pumping at the depth below 300 m in the Yunlin area, this study will establish a heterogeneous hydrogeological model within the depth range of the sedimentary layer. The developed model will be used to assess the contribution of shallow pumping to subsidence below 300 m and whether there is deep pumping. This study collects geological drilling data in the Yunlin area, sorts and classifies the geological data, inputs the drilling data into the GMS program to construct the drilling data, and then uses the Markov chain method to analyze the hydrogeological data to develop the hydrogeological model of Yunlin area. Then, the groundwater flow model is established with the MODFLOW program, and the subsidence model is established with the SUB program, and then the models will be calibrated and validated. The developed numerical model will be used in water balance analysis to understand the spatial and temporal distribution characteristics of groundwater pumping and recharge in the study area. Then, carry out hypothetical scenario simulations to evaluate the mitigation of groundwater subsidence by decreasing or stopping groundwater pumping. The study results can provide a reference for groundwater resource management and further investigations.