Groundwater Flow Monitoring via Joint Time-lapse Electrical Resistivity and Self Potential Data Tomography
Lige Bai1, Jing Li1*, Hui Liu1, Jaiwei Tan1, Tianqi Wang1
1 College of geo-exploration Sci. &Tech, Jilin University, Changchun, Jilin 130026, China
*Corresponding author: Jing Li,inter.lijing@gmail.com
Key words: Groundwater Flow Monitoring; Time-lapse; Electrical Resistivity Tomography (ERT); Self-potential (SP) Tomography
Funding Information: This work are supported by the Natural Science Foundation of China (41874134), the Jilin Excellent Youth Fund (20190103142JH) and the China Postdoctoral Science Foundation 2015M571366
Summary
Revealing the dynamics of groundwater movement in the vadose zone is crucial to groundwater management and artificial recharge. In this study, the groundwater flow characterization of the pumping process is monitored by the joint time-lapse electrical resistivity tomography (ERT) and self-potential (SP) data tomography. The ERT data invert the resistivity distribution, which relates to the variation of soil moisture content during the pumping process. Base on the groundwater motion feature, the SP data provide a direct way to invert the current density and estimate the permeability. A total of 24 hours of time-lapse surveys show a significant increase and decrease in resistivity and permeability during water pumping and groundwater recharge, which suggests groundwater decline and recovery process. These results have an excellent agreement with the groundwater level monitoring result. Combining ERT and SP data can provide a reliable way in groundwater or other hydrogeological surveys.