Fig. 8. (a) True moisture content at t = 50000 min; (b) estimated at t = 50000 min without measurements; (c) estimated at t = 50000 min with 20 measurements. (d) Schematic diagram for three-dimensional electrical resistivity tomography experiments. Top center square indicates the infiltration area, right triangles indicate voltage measurement locations, circles show current source locations, and squares show the locations of 20 measurements. (e) The scatter plot corresponding to (b); (f) the scatter plot corresponding to (c).