Geoelectric Field Response to Seepage in Sand and Clay Formations

Abstract

An understanding of groundwater flow in soil and rocks is necessary for civil and environmental engineering. Real-time monitoring of groundwater flow is a relatively new research area. This paper presents an experimental investigation into the response of geoelectric fields to the steady flow of water through a heterogeneous sand and clay medium. The parameters of the geoelectric field were measured during seepage. The self-potential decreased gradually and then increased rapidly when the infiltration front passed reference electrode N at 3 min. The self-potential decreased rapidly when the infiltration front reached an electrode. Stepwise changes in the current were used to calculate the seepage velocities in different media. The apparent resistivity decreased rapidly to below 600 Ω·m when the water reached each electrode. Therefore, geoelectric fields can be used to monitor water flow in real time.