%ARanaivo Nomenjanahary, F
%ARakoto, H [Institute of Geophysical Observatory, Antananarivo (Madagascar)]
%ARatsimbazafy, J B
%D1994
%I; International Centre for Theoretical Physics (ICTP), Trieste (Italy)
%J
%K54 ENVIRONMENTAL SCIENCES, ELECTRICAL SURVEYS, DATA PROCESSING, ELECTRIC CONDUCTIVITY, ALGORITHMS, GEOLOGIC STRUCTURES, MAGNETOACOUSTIC WAVES, NONLINEAR PROBLEMS, ONE-DIMENSIONAL CALCULATIONS, STOCHASTIC PROCESSES, 540250, SITE RESOURCE AND USE STUDIES
%PMedium: X; Size: 16 p.
%TAn approximate inversion method of geoelectrical sounding data using linear and bayesian statistical approaches. Examples of Tritrivakely volcanic lake and Mahitsy area (central part of Madagascar)
%XThis paper is concerned with resistivity sounding measurements performed from single site (vertical sounding) or from several sites (profiles) within a bounded area. The objective is to present an accurate information about the study area and to estimate the likelihood of the produced quantitative models. The achievement of this objective obviously requires quite relevant data and processing methods. It also requires interpretation methods which should take into account the probable effect of an heterogeneous structure. In front of such difficulties, the interpretation of resistivity sounding data inevitably involves the use of inversion methods. We suggest starting the interpretation in simple situation (1-D approximation), and using the rough but correct model obtained as an a-priori model for any more refined interpretation. Related to this point of view, special attention should be paid for the inverse problem applied to the resistivity sounding data. This inverse problem is nonlinear, while linearity inherent in the functional response used to describe the physical experiment. Two different approaches are used to build an approximate but higher dimensional inversion of geoelectrical data: the linear approach and the bayesian statistical approach. Some illustrations of their application in resistivity sounding data acquired at Tritrivakely volcanic lake (single site) and at Mahitsy area (several sites) will be given. (author). 28 refs, 7 figs.
%0Technical Report
IAEA Other: ON: DE95612415; TRN: XA9438431010242 INIS English