Exploring the Model Space of Airborne Electromagnetic Data to Delineate Large-Scale Structure and Heterogeneity within an Aquifer System

Abstract

The airborne electromagnetic (AEM) method can play an important role in the study and management of groundwater systems, by providing a model of the subsurface that captures the large-scale variation in lithology or sediment type throughout a survey area. A typical workflow for the interpretation of AEM data involves the compilation and review of all relevant ancillary data from the survey area (e.g., driller's logs, geophysical logs, and geological cross-sections); the initial processing of the acquired data, to remove low quality data (Auken et al., 2018); the inversion of the data, to recover the electrical resistivity distribution in the subsurface and define a resistivity model (

Managed aquifer recharge site assessment with electromagnetic imaging: Identification of recharge flow paths

“…The resistivity model at each site, recovered through inversion of the tTEM data, is nonunique, meaning that many resistivity models could fit the data equally well. We accounted for the uncertainty in the inversion by generating 100 resistivity models at each site using a posterior sampling (PS) technique (Kang et al., 2021; Rue, 2001), which used the recovered resistivity model as an input. This technique uses a linear approximation and assumes a Gaussian posterior distribution.…”

Improved Imaging of the Large‐Scale Structure of a Groundwater System With Airborne Electromagnetic Data

“…The airborne electromagnetic (AEM) method is potentially a highly effective means of imaging large‐scale structure for the development of a groundwater model (Barfod et al., 2018; Foged et al., 2013; He et al., 2014; Kang et al., 2021; Knight et al., 2018; Sattel & Kgotlhang, 2004; Wynn, 2002). Inversion of the acquired AEM data recovers a resistivity model of the subsurface.…”