SELF-POTENTIAL INVERSION FOR THE ESTIMATION OF PERMEABILITY STRUCTURE

Abstract

ABSTRACT The self-potential (SP) method is one geophysical method useful for estimating properties of groundwater flow. The effect of a permeability anomaly on a SP profile has been discussed in the literature, but neither the feasibility of using SP measurements to estimate the permeability structure nor the resolution of the inversion results of an SP profile have been given much attention. In this study, we developed a two-dimensional inversion code for the estimation of permeability structure. We applied this inversion to a synthetic SP profile on the ground surface affected by the permeability structure to evaluate the resolution of the SP inversion. Four models, which include a permeability anomaly located in the center of a slope, are used for the evaluation of the inversion performance. A priori data, including the distribution of the streaming current coefficient, electrical conductivity and flux volume at the discharge and recharge, are input to the inversion. A horizontal zone with high permeab...