THE EFFECT OF 2-DIMENSIONAL TERRAIN WITH POINT-SOURCE ON RESISTIVITY SURVEYS

This paper uses the boundary element method to solve the problem of th e effect of two-dimensional terrain with point current source on resis tivity surveys. First, the 3-D boundary value problem of the electric field of a point source on 2-d terrain is converted into a 2-D boundar y value problem using a Fourier transform. Then, the 2-D boundary valu e problem is transformed into a boundary integral equation by means of Green's formula. The boundary element method is used to solve the int egral equation. Finally, using an inverse Fourier inverse transform, w e get the electric potential in 3-D space. ExamPles calculated for two terrain models show that the results from this method compare well wi th those from analytic and finite element method. If the terrain has a clear strike, this method can be used for terrain corrections for res istivity surveys. An example of a terrain correction for electric soun ding is given. This method can be run on a personal computer and takes a few minutes to correct a profile of data on an IBM AT -grade comput er.