On the correspondence between resistivity and texture of loose sediments, saturated with salt water

Electrical resistivity tomography (ERT) has been applied to characterize coastal aquifers heavily affected by the problem of groundwater salinization. With the help of a number of resistivity data sets and control boreholes, separate resistivity ranges were related to sand-grained sediments, saturated with salt water, and fine-grained sediments, silts and clays, deposited in a sub-marine environment. Frequency-domain electromagnetic soundings (FDEM) were then used to map the spatial resistivity variations in a selected site of the study area. One-dimensional inversion of FDEM real and imaginary parts provided a quantitative resistivity–depth model that was consistent with the ERT model section and direct borehole observations. The successful application of the FDEM technique supports its use for mapping shallow fluid pathways of salt-water intrusion over large areas.