Application of joint inversion of electrical resistivity data to determine the geometric distribution of municipal sewage leaks (a case study in the Masjedsoleyman town)

To determine the probability of sewage infiltration into foundations of unborn structures, the Werner and the dipole - dipole arrays were used in an electrical resistivity tomograph operation in Masjed Soleiman City which is located in south west of Iran. Using Robust Constraint and Combined Marquardt and Occam algorithms, the measured apparent data were inverted to true electrical resistivity values separately then joint inversion was carried out using the data gathered by both arrays. Three drilled boreholes along the electrical resistivity profile were very useful in accurate interpreting the results. The Combined Marquardt and Occam algorithm provided better results than the Robust Constraint for presenting a subsurface electrical resistivity mode. Also, the electrical resistivity model resulting from the joint inversion of the Werner and dipole - dipole array data is more consistent with reality than the individual inversion of the data for each array.