探地雷达和电阻率法探测LNAPL污染土壤研究

his paper presents the effectiveness of electromagnetic (EM) exploration techniques for detecting near-surface soil contaminants. Field work has been done at a former industrial site containing light non-aqueous phase liquid (LNAPL) in soils. The experiment shows that a combination of ground penetrating radar (GPR) and electrical resistivity can provide an effective means of mapping subsurface contamination. Soil cores sampled in the three boreholes clearly indicate that the concentration of total petroleum hydrocarbons (TPH) has an inverse relation to the relative dielectric constant and a direct proportional correlation with the electrical resistivity.GPR data have high spatial resolution and enable us to image the shallow subsurface stratigraphy, although its depth of penetration is greatly limited in a conductive region. The electrical resistivity method is effective to obtain the resistivity structure associated with the subsurface stratigraphy and the contamination zone. Three-dimensional GPR and resistivity images are constructed to map LNAPL contamination which is illustrated by the decreased radar signal amplitude and increased resistivity.