Analysis on the dynamic variations of well water temperature: With example of the Dangxiao well in Lijiang area, Yunnan Province

With example of the Dangxiao well in Lijiang city of Yunnan Province, we analyzed the basic and coseismic variations of the water temperature, and discussed the possible precursory anomalies. As for the basic variation of water temperature and water level in the Dangxiao well, the comparison results combined with the well water temperature gradient show that, the temperature sensor in the Dangxiao well is located at the main section where the well water intersects with the aquifer, and the recharging source is relatively cold. The water temperature variation is mainly affected by the discharge status and the variation of water level. As for the coseismic variations of the water temperature in the Dangxiao well, when the coseismic variation of water level displays as oscillating, it shows obvious differences, displaying as ascending−descending−recorvering during artesian status and descending−ascending−recovering during non-artesian status. The coseismic variations of water temperature also verify the location of water temperature sensor and cold source recharging, which is consistent with the conclusion obtained from analysis of the basic variation aspect. As for the precursory variations, the water level variations in the Dangxiao well are influenced by the tendency of rainfall, and the strong water activity could be found at the location of the temperature sensor in the Dangxiao well, which may suppress the precursor information to some extent, so it is hard to find evident precursor in the water temperature variation.