Synthetic modeling of EM34 in detecting the shallow clayey layer in aquifer system

Abstract

It is essential to get information on clayey layers, which may play a significant role in protecting shallow aquifers thanks to their low hydraulic conductivity from surface contamination. One of the simple geophysical instruments is EM34 which applies the electromagnetic principle to read directly and quickly the apparent electrical conductivity of the subsurface. To evaluate the EM34's detectability of clay, a total of 42 synthetic models were built at different top depths and thicknesses of clay between sand layers. Synthetic models were then transferred and added 2% random noise and interpreted followed to a procedure by using IX1D software. The comparison of synthetic models and new interpreted models gives potential results that EM34 is well able to detect the presence (the thickness and the top depth) of the shallow clayey layer from the surface to 30-meter depth.