Time-lapse resistivity imaging is one of the effective approaches for monitoring dynamic conductivity changes in shallow subsurface.In practice,due to temporal variations in observation noise,electrical structural changes derived from individual inversions may contain false information,increasing the difficulty in interpreting the time-lapse resistivity results.In this study,the time-lapse constraint is applied to the traditional regularized inversion objective function to control the electrical difference at adjacent time points,thereby suppressing the spurious changes caused by time-varying noise.The three-dimensional(3D)time-lapse resistivity inversion approach is then realized by using the limited memory quasi-Newton method.The inversion results of synthetic data show that,compared with the results of individual inversion,time-lapse method can better suppress the influence of noise and obtain more accurate electrical structure changes.Field experiments show that time-lapse inversion can more closely reveal the actual electrical structure changes.These results suggest that time-lapse inversion can suppress false anomalies caused by background noise and improve the accuracy of inversion results.This study provides an effective way to monitor the dynamic changes of electrical structure in shallow subsurface.
维普
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