High-Resolution Airborne Electromagnetic Surveying for Dryland Salinity Management: The Toolibin Lake SkyTEM Case Study, W.A.

Abstract

A trial SkyTEM helicopter EM survey was flown over Toolibin Lake in southwestern Australia in October 2006, with the intent of establishing the suitability of this system for the detailed mapping of landscape variability in Australian settings. Survey results are in close agreement with those from a TEMPEST airborne electromagnetic survey flown in 1998, as well as an earlier AEM survey using the SALTMAP system. The Toolibin Lake SkyTEM data were interpreted using the laterally-constrained inversion (LCI) approach. Both few-layer and smooth-model LCI inversion have been applied to the Toolibin Lake SkyTEM dataset, and examples of both styles of inversion presented here demonstrate the high near-surface resolution of the SkyTEM system. Repeatability of the SkyTEM data is shown via analysis of repeat measurements on a test survey line. LCI is shown to provide a high-quality image of subsurface conductivity delimiting a known palaeochannel system. It also provides much-improved parameter resolution over more conventional layered-earth inversion indicating the applicability of the SkyTEM system for providing baseline information on landscape characteristics that are relevant for salinity management in dryland catchments.