Karst Mapping Using Airborne Electromagnetics – Multi – Layer Inversion to Derive Spatially Distributed Parameter

Karst aquifers represent important but very vulnerable sources for water supply to a significant part of the earth’s population. For sustainable use of these resources, development of integrated management tools based on numerical groundwater models is required. However a flow model for karst aquifers requires detailed, spatially distributed information on the flow- relevant characteristics of the subsurface. Methods determining the distribution of the electrical resistivities within the subsurface could provide such information. To explore the potential of airborne electromagnetic mapping for providing such innovative input information, the international scientific research initiative XPLORE was initiated. Within this paper, successful approaches to derive the subsurface cave structure and to map the depth of the halocline using multi-layer 1D inversion of frequency domain electromagnetic data are presented.