The Application And Research Of High- Frequency Magnetotelluric Method In The Groundwater Exploration

Magnetotelluric sounding is based on the classical theory which is proposed by Tikhonov(ANTikhonov, 1950) and the Kania(L.Cagnird, 1953).Currently, the Magnetotelluric sounding method plays an important role in theconcealed metallic mineral exploration, earthquake prediction, volcanic structure in deep oil, crustal lithospheric structure research,covered karst water structure, geothermal field investigation and other fields.Magnetotelluric forward calculation is the important means to detect the electromagnetic responses of subsurface geologicalbody. Magnetotelluric inversion can restore the underground electrical distribution through the existing magnetotelluric information.Therefore, Magnetotelluric forward simulation and inversed calculation to the subsurface geologicalbody can make us have a better understanding of magnetotelluric response and discipline.In order to reflect the distribution of adverse geological body veritably, the article bases on the magnetotelluric forward simulation to direct the inversion interpretation. The main contents including the following aspects:The main contents including the following aspects:1) Analyzing the research current situation of the magnetotelluric forward and inversion and expounding the foremost research content and the arrangement of the structure.2) Studying the basic principle of the magnetotelluric sounding. To derive wave equation and boundary equations from Maxwell’s equations, and to analysis magnetotelluric expression under the conditions of homogeneous half space and two layer geological.3) Studying the basic principle of the magnetotelluric forward. Focuses on using the finite element method to solve magnetotelluric forward problem. The numerical simulation of finite element forward modeling, the finite element mesh, boundary value problem, and variational problem on the one-dimensional and two-dimensional models have been derived in detail.4) Studying the basic principle of the magnetotelluric inversion. Research on based on a priori constraints regularized inversion, least squares smooth constrainedinversion, as well as the objective function of two-dimensional inversion methods which are used frequently.5) Studying the principle and field work method of the EH4 electromagnetic sounding system,and apply it on the project of groundwater resources exploration in a region of Ning Xia.Based on hydrogeological conditions and geophysical features of the research district, and combined with the results of previous studies, processing the measured data with the method of RRI, providing geological interpretation and making the evaluation of groundwater quality.6) Summarizing the research achievements, the existing problems and future research directions of the thesis.