نوع مقاله : مقاله پژوهشی
نویسنده
دانشکده مهندسی معدن و متالورژی، دانشگاه یزد، یزد، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسنده [English]
Quantitative interpretation of electrical resistivity tomography (ERT) and electromagnetic in low induction number (EM-LIN) data sets is possible through inversion. Data inversion of the two methods is confronted with two problems of non-uniqueness and instability, which must be solved by the use of constraints and a priori information. The more important issue is that implementation of one geophysical method does not lead to a favorable interpretation of the subsurface structure in many cases, so the combination of geophysical data is inevitable. In this paper, joint interpretation of resistivity and electromagnetic in low induction number data are used for a site in South Africa. In this area, the identification of dolerite dyke is the most important goal in the exploration of underground water. Herer, a 2D forward modeling code for EM-LIN and ERT is developed based on the integral equation (IE) method. Also, a linear relation between model parameters and apparent conductivity values is proposed. To invert both data sets, the weighted minimum length solution algorithm is used, and the depth weighting function is used as the model weighting matrix. The inversion of electromagnetic in low induction number indicates a relatively thick dyke in the depth range of less than 5 to 15 m and with a horizontal extension of 185 to 200 m (thickness is about 15 m). Electrical resistivity tomography recovers a two layered medium, and in the conductive layer close to the surface of the dyke, a resistive dyke is extended to near the surface. In fact, the electromagnetic method reconstructs the dyke better, while electrical resistivity tomography is able to recover the layered structure.
کلیدواژهها [English]
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