Dc resistivity and time-domain induced polarization survey for the study of groundwater contamination in bahia, brazil

摘要

DC resistivity and time-domain induced polarization (IP) measurements were performed near an open-air basin which was used for many years by a huge petrochemical complex in Bahia, Brazil, as a site for liquid organic and inorganic waste disposal. 1-D inversion of resistivity measurements delineated the local geological structure, as well as contaminated zones indicated by conductive anomalies. 3-D DC forward modeling was employed to examine lateral effects of a lake as a possible reason for these anomalies. Finally, the interpretation of the chargeability data allowed the distinction between the local occurrence of lenses of shale and contaminated ground regions, which could not be inferred through resistivity measurements alone.