SEGJ Technical Conference

Estimation of water head and permeability structure with the Self Potential inversion

Abstract In this study, we developed the 2D inversion programs that estimate both the water head distribution and the permeability structure from Self-Potential(SP) profile according to Sheffer (2008) and Carrera et al. (2005). We applied these inversion programs to the synthetic SP profile. The synthetic SP profile, used as observed data for the inversions, is evaluated with a modeled slope with 800m length and 40m height difference. The permeable anomaly is located in the center of the model and the pattern of synthetic SP profile is affected by the subsurface permeable anomaly. The permeable anomaly makes the water head distribution sparse and changes the pattern of SP profile. We tried to reconstruct the water head distribution and permeability structure from the distorted SP profile by the permeability anomaly. A priori information of the water heads at two points for water head inversion. For the permeability inversion, the discharge and recharge of groundwater are given. The estimated water head shows both smooth distribution in the whole area and sparse change at the permeability anomaly, similar to the synthetic pattern. The estimated permeability anomaly also appears at the same place of the permeable anomaly of simulated model. From these results, our two inversion programs are useful to estimate both the water head distribution and the permeability structure.