Quantifying model structural uncertainty and facies prediction for locating groundwater supplies in Timor-Leste using AEM data

Abstract

Geological structures key to understanding groundwater resources in Timor-Leste’s Baucau Plateau are mapped using an airborne electromagnetic (AEM) survey. A comprehensive assessment of model structural uncertainty is conducted using a Bayesian Markov chain Monte Carlo algorithm, and an approach for translating geophysical to geological model uncertainty is introduced. A prominent feature of the Baucau survey is a very high-contrast transition from resistive limestone materials to conductive clays, which is well-resolved from the AEM analysis. The inferred 3D geometry of potentially water-bearing limestone units that overly relatively impermeable clays is a key outcome of this analysis, and will be the focus of future ground-truthing efforts.