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A general approach of inferring 'derived products' from AEM inversion results
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 6th International AEM Conference & Exhibition, Oct 2013, cp-383-00022
Abstract
The physical parameter found from interpreting AEM surveys, the distribution of subsurface conductivity, is interesting in itself only in very few instances. In most cases the conductivity distribution will have to be translated to provide information on the actual target properties of the survey: sand/clay (geological interpretation), saturated/unsaturated and fresh/salt (hydrogeological interpretation), polluted/not-polluted (biohazard/geotechnical interpretation); estimation of hydraulic conductivity (hydraulic modeling); pristine/disturbed (forensic interpretation), etc. The parameters of these categories are often called "Derived Products". The translation process can be done in a wide variety of ways: from a predominantly qualitative approach based on professional experience to an application of rigorous quantitative relations found from scientific endeavors. In most practical situations, the number of locations with independent information on the Derived Product is considerably smaller than the number of geophysics locations; it is precisely the scarcity/sparsity of information on Derived Product that encourages the use of geophysical inversion results as a sort of qualified interpolator through a formulation of a functional relation between a geophysical parameter and the parameter of the Derived Product. We present a general, quantitative, inversion-based approach to deriving the parameter of interest. Three different methods are presented and compared through numerical simulation with a few illustrative examples.