Modified two-step Levenberg-Marquardt methods in the hydraulic conductivity identification problem

Some modifications of two-step Levenberg–Marquardt methods are proposed for the minimization of a residual function. The methods are used to numerically solve a model problem of hydraulic conductivity identification for a three-dimensional anisotropic confined aquifer. The efficiency of the modified two-step Levenberg-Marquardt methods is shown for the problems with and without errors in pressure measurements.