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Abstract Multiplicity of solutions to inversion is a inherent problem of 3D electrical resistivity detection，which always causes errors and even mistakes in the geological interpretation. A research thought is presented to solve the problem，in which the structural and morphology information of anomalous body gained by other geophysical methods，e.g. seismic prospecting，ground penetrating radar，is used as prior constraints in resistivity inversion. First，construction method of a novel constraint named spatial structural constraint is proposed. The known anomalous regions obtained with other geophysical methods are mapped into 3D inversion model；and the difference between grids in corresponding regions is restricted to minimum. Thus，spatial structural constraint matrix is established to characterize typical geological structures，especially the more complicated structures；and it is relatively easy to be expressed mathematically and constructed. Based on above research，the objective function and inversion tomography equation of 3D resistivity inversion with spatial structural constraint are constructed. Then，numerical tests and engineering application are implemented；and the spatial structural constraint gained by ground penetrating radar(GPR) is applied to 3D resistivity inversion. It is found that the prior information increases greatly and false anomaly in inversion tomography is eliminated effectively. And the location precision and interface identification-effect are improved significantly compared with traditional method，making the inversion result be consistent with geological model or actual situation and the multiplicity of solutions be pressed obviously. And it is proved that the 3D resistivity inversion tomography with spatial structural constraint is a feasible way to reduce multiplicity of solutions and improve location precision and interface identification-effect.
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Received: 18 July 2012
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2012, Vol. 31 
