Groundwater Flow Monitoring via
Combined Time-lapse Electrical Resistivity and Self Potential Data
Tomography
Lige Bai1, Jing Li1*, Li
Guo2,3, Hui Liu1, Jaiwei
Tan1, Tianqi Wang1
1 College of Geo-exploration Sci. &Tech, Jilin
University, Changchun, Jilin 130026, China
2 State Key Laboratory of Hydraulics and Mountain
River Engineering, College of Water Resource and Hydropower, Sichuan
University, Chengdu 610065, China
3 Department of Ecosystem Science and Management,
Pennsylvania State University, University Park, PA 16802, USA
*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. The
traditional hydrographic surveys are usually indirect, costly, and
infrequent. In this study, the groundwater flow characterization of a
pumping experiment in Jilin University campus was monitored through
combining time-lapse electrical resistivity tomography (ERT) and
self-potential (SP) data tomography. The ERT datum depicts the spatial
distribution of resistivity, which is related to the dynamics of soil
moisture content during the pumping process. We are able to correlate
hydraulic heads and SP signal during a decline and recovery groundwater
level period leading to interesting perspectives in understanding the
dynamics of complex groundwater flow. The SP method provides a direct
way to estimate the potential field distribution, which can be further
used to invert soil permeability. A total of 24 hours of time-lapse
geophysical surveys revealed a significant increase in resistivity but a
decrease in permeability during water pumping and groundwater recharge,
representing the process of groundwater decline and recovery. Results
derived from time-lapse geophysical surveys matched well with in
situ monitoring of the groundwater level. The study demonstrates that
the combined ERT and SP data can provide a direct and reliable way to
monitor groundwater flow or other time-lapse hydrogeological surveys.