Abstract: In order to improve the detecting capability for soil layer contaminated with oil sewage, the resistivity changes of soil layer, prior to and after the contamination, were analyzed. A geoelectrical resistivity model is established for such resistivity change analysis. The resistivity anomaly sections of Wenner, Schlumbeger, dipoledipole and polepole array were calculated with 2.5-D finite element method (FEM). The forward results show that the detecting capabilities of different arrays are different from each other. Comparatively, Wenner and Schlumbeger array image better the contaminated area. The calculated results also show that the electrical resistivity of the contaminated saturation soil is higher in Wenner array, and the resistivity anomaly area matches the contaminated area. The field study also favors this analysis.

Key words: contaminated soil, electrical resistivity method, numerical modeling, anomaly characteristic