Giving Non-Uniform Initial Model in 2D Inversion with Vertical Electrical Sounding Data

In order to improve the convergence rate and inversion precision in 2D inversion of vertical electrical sounding,to give the initial model of 2D inversion applying the formula of approximate inversion is put forward.During the approximate inversion,the accurate inversion result is got by comprehensive utilizing cubic spline method,five points method and Neville interpolation to compute the gradient values of every electrode spacing of electrical sounding curve and modifying the depth of approximate inversion result,providing good initial model for the 2D inversion.The feasibility and effectiveness of the non-uniform initial model by approximate inversion method to 2D inversion are verified through inverting the simulated and measured vertical electrical sounding data.