Real-Time Monitoring and Simultaneous Verification of Water Percolation Using Electrical Resistivity Tomography and Photography Techniques

Water percolation usually occurs in soil, making it highly challenging to simultaneously monitor and verify the water percolation process in real-time. We propose employing electrical resistivity tomography and the photography technique, respectively, to visualize and validate water percolation. An experiment was conducted to monitor water percolation in sand within a transparent glass trough using electrical resistivity tomography (ERT) and photography techniques. The experimental results show that the relatively low-resistivity anomalies in the electrical resistivity profiles and correction electrical resistivity profiles, derived from the experimental data, have a half-ellipse shape, while the wetting areas captured in the photographs exhibit a bulb-shaped pattern. The relatively low-electrical-resistivity anomaly areas delineated by the 2000 Ω·m contour line in the electrical resistivity profiles and the 120 Ω·m contour line in the correction electrical resistivity profiles exhibit a remarkable correspondence with the wetting areas captured in the simultaneous photographs. Our findings show that the ERT and photography techniques are suitable for the real-time monitoring and simultaneous verification of water percolation in sand within a narrow glass trough.