A Wenner array routine for optimum electrode spacing selection for resistivity measurements over thin subsurface media

Abstract This study was carried out with a view to establishing routine for the selection of optimum electrode spacing accurate measurement resistivity within unusually thin (5–100 cm) subsurface layer in agro geophysics. The Hummel’s image theory 2-Layer Wenner Vertical Electrical Sounding (VES) formed theoretical basis study. For purpose simulation, computer program developed using theory. simulation process involved varied upper and lower resistivities conjunction spectrum spacings (a) thicknesses (h). relationship between thickness determined asymptotic characteristics model curves sensitivity models obtained from simulation. deduced relationships were validated same approach on field data. It observed that respect thickness, limits remained irrespective nature (resistive or conductive). On other hand, factor attainment its resistivity. observations data congruous those Very strong (R = 0.99) direct linear existed identified will keep measurements little no interference underlying is less than half thickness. Also, not six times required accurately measure when resistive. However, conductive layer, an about twelve true layer.