Characteristics of Coseismic Responses Groundwater Temperature and Level of Yunnan Well Network to Several Earthquakes

Based on the coseismic response data of water temperature and water level of 27 observation Wells in Yunnan well network from 2008 to 2023, the co-seismic response characteristics of water temperature and water level of each observation well are compared and analyzed with 8 earthquakes that have a significant impact on Yunnan region. The co-seismic response mechanism is discussed from the perspectives of seismic wave energy density, lithology, control of fault zone and dynamic coordination. The results indicate that the response of water temperature and water level in the well pattern of Yunnan to the far-field earthquake is more significant than compared to near earthquakes, with the response primarily concentrated in the middle of Yunnan. The water level exhibits a more pronounced response than the water temperature. The co seismic variation of water level is mainly characterized by oscillation and rise, while the water temperature is mainly characterized by pulses. Dehong FaPa Dian No.22 well and Lijiang Xiagshan well have better seismic reflection performance in Yunnan well pattern, On the other hand, wells No.06 in Jianchuan, No.01 well in Huize Gangou town, Xiaoshao well in Kunming Guandu District, Dayao Geothermal well, and Nanhua Zhen 2 well exhibit weaker co-seismic responses compared to the other 22 wells. Further analysis shows that the linear fitting correlation coefficient between Seismic wave energy density and epicenter distance is greater than −0.9, which is significantly negative correlation and positive correlation with magnitude, and shows the corresponding relationship between energy density and permeability coefficient. Finally, we analyzed the mechanism of coseismic response of water temperature and water level.