Publication Date:
2017-04-04
Description:
In the past three decades, airborne electromagnetic (AEM) systems have been used for
many groundwater exploration purposes. This contribution of airborne geophysics for both
groundwater resource mapping and water quality evaluations and management has increased
dramatically over the past ten years, proving how these systems are appropriate for large-scale
and efficient groundwater surveying. One of the major reasons for its popularity is the time and
cost efficiency in producing spatially extensive datasets that can be applied to multiple purposes.
In this paper, we carry out a simple, yet rigorous, simulation showing the impact of an AEM
dataset towards hydrogeological mapping, comparing it to having only a ground-based
transient electromagnetic (TEM) dataset (even if large and dense), and to having only boreholes.
We start from an AEM survey and then simulate two different ground TEM datasets: a high
resolution survey and a reconnaissance survey. The electrical resistivity model, which is the final
geophysical product after data processing and inversion, changes with different levels of data
density. We then extend the study to describe the impact on the geological and hydrogeological
output models, which can be derived from these different geophysical results, and the potential
consequences for groundwater management. Different data density results in significant
differences not only in the spatial resolution of the output resistivity model, but also in the
model uncertainty, the accuracy of geological interpretations and, in turn, the appropriateness
of groundwater management decisions. The AEM dataset provides high resolution results and
well-connected geological interpretations, which result in a more detailed and confident
description of all of the existing geological structures. In contrast, a low density dataset from a
ground-based TEM survey yields low resolution resistivity models, and an uncertain description
of the geological setting.
Description:
Published
Description:
53-66
Description:
7A. Geofisica di esplorazione
Description:
JCR Journal
Description:
restricted
Keywords:
Airborne electromagnetics, Time domain electromagnetics, Hydrogeophysics
;
04. Solid Earth::04.05. Geomagnetism::04.05.08. Instruments and techniques
;
05. General::05.01. Computational geophysics::05.01.01. Data processing
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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