为进一步解决传统直流电法正演计算中所存在的问题,给出了基于有限体积法的直流电阻率法2.5维数值模拟算法。针对数值模拟中至为关键的场源奇异性及边界效应,介绍了一种右端项校正技术。通过构建若干典型的地电断面模型,计算地表电位及视电阻率,并对其异常响应进行分析。算例结果表明,通过校正方程组右端项后产生的源矢量不再是包含近源处突变电位的矢量,它能够补偿正演算符因边界取得不够远而丢失的信息,进而减少边界及源奇异性对正演模拟的误差,验证了本文算法的可行性。
In order to slove the problems of the direct current (DC)resistivity method using traditional forward algorithm ever further,2.5 dimensional numerical modeling for DC resistivity method based on finite volume method is introduced .A correction technique is proposed for the right-side of FVM equation to solve the source singularity problem and boundary effect in numerical modeling.Numerical tests are carried out using several typical geo-electrical models.The specific properties of the electric potential on the surface and apparent resis-tivity are illustrated and numerical accuracy is verified.The numerical experiments show that the new source term contains additional information correcting the errors in the forward operator and compensates the boundary effects and the source singularity.