直流电阻率法的深部结构分辨——三维模型的二维反演

Resolution of deep structures for DC resistivity method:2D inversion for 3D model

利用三维有限差分方法进行深部三维结构的电阻率三维数值模拟,对计算得到的单极-单极和对称四极装置视电阻率剖面进行电阻率二维反演研究。结果显示:单极-单极装置在横向上只要三维异常体中心的水平间距不小于两者中心埋深之和,就可以基本将2个三维结构分辨出来;相同情况下,对称四极装置在横向上的分辨效果优于单极-单极装置;单极-单极装置在垂向上的分辨要优于对称四极装置。

Numerical simutation for 3D model with deep structures was carried out by using 3D finite difference resistivity modeling method. 2D inversion of calculated apparent resistivity profiles of pole-pole and symmetric four-pole sounding was studied. The result indicates that pole-pole system can resolve 3D structures if the hori- zontal interval of the center of 3D abnormal bodies is not less than the total depth of the center of the two structures Under the same conditions, symmetric four-pole system has horizontal resolution better than pole-pole system, and pole-pole system has vertical resotution better than symmetric four-pole system.