Thus the changes in the wellbore skin zone will not have a significant effect on the tidal response of the aquifer as a whole. In our data, for all wells that recovered within several days, we do not see a phase change in the tidal response. For those wells that have longer water level recovery time (more than one month), tidal analysis results also show that their permeability in the aquifer changed, consistent with our model to explain transient and persistent water level changes. Moreover, if the coseismic well water level changes are caused by the fluid pressure changes immediately adjacent to the wellbore (e.g., in the skin zone), the well level in the well and aquifer pressure will equilibrate at least as quickly as the step response to surface loading, and this response will be completed in about 37 h(using T=2.4 ×10−5m2/s, S=5.0 ×10−4, and a thickness of skin zone of 5cm