Azimuthal Resistivity Surveys Over a Fractured Landfill Cover

Abstract

Azimuthal resistivity surveys were assessed as a means of identifying and characterizing landfill cover fractures through a small-scale experiment in which azimuthal resistivity variations were measured over fractured and unfractured cover under both moist and dry conditions. Soil moisture tensions and rainfall were also recorded. Fracture trends did not always correspond to azimuths of increased apparent resistivity, suggesting the standard anisotropic resistivity model often used to identify fractures is inappropriate in this setting. Fractured cover materials, however, exhibited higher average resistivities and greater azimuthal resistivity variation than unfractured cover materials, particularly during dry periods. Azimuthal resistivity surveys should be tested further, utilizing these results, over landfill covers containing buried fractures or fractures hidden by vegetation.