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@PHDTHESIS{Gting:834749,
author = {Güting, Nils},
title = {{H}igh resolution imaging and modeling of aquifer
structure},
volume = {383},
school = {Ruhr-Universität Bochum},
type = {Dr.},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
reportid = {FZJ-2017-04645},
isbn = {978-3-95806-253-5},
series = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
Umwelt / Energy $\&$ Environment},
pages = {viii, 107 S.},
year = {2017},
note = {Ruhr-Universität Bochum, Diss., 2017},
abstract = {Predictive modeling of groundwater flow and solute
transport can help to protect groundwater resources and to
remediate contaminated sites. It is challenging, however,to
develop realistic groundwater models because it is difficult
to characterize and model the complex heterogeneity of
geologic media. In this work, we propose an approach that
combines high resolution geophysical imaging and
multiple-point statistical modeling to estimate the 3-D
structure of aquifers. Our study is carried out at the
Krauthausen site, Germany, where 15
cross-boreholeground-penetrating radar (GPR) data sets were
acquired in an all uvial sand and gravel aquifer. To analyze
the GPR data, we apply a recently developed full-waveform
inversion approach that is preferable, in terms of spatial
resolution, over traditional ray based inversion approaches.
By stitching together the inverted tomograms from adjacent
crosshole planes, we are able to image, with a
decimeter-scale resolution, the aquifer’s electrical
properties (dielectric permittivity and electrical
conductivity) along vertical cross-sections up to 50 m long
and 10 m deep. Comparison of the GPR results with co-located
direct-push profiles shows a strong correlation between the
porosity derived from GPR dielectric permittivity and the
porosity derived from direct-push neutron logs. We can show
that the dielectric permittivity obtained from full-wave
form inversion more accurately reconstructs sharp contrasts
and fine-scale variations in porositythan the dielectric
permittivity obtained from traditional ray-based inversion.
One problem with using GPR for hydrogeological site
characterization is that GPR yields electrical properties
which are only indirectly linked to hydraulic properties. We
present two approaches to estimate hydrogeological facies
from the GPR results. The first approach, based on k-means
cluster analysis, is applied to GPR data from five adjacent
crosshole planes. Cluster analysis of the GPR results
suggests three facies. Densely spaced cone penetration
tests, located along the GPR transect, confirm the number of
facies and their spatial distribution in the aquifer
cross-section. Grain size distributions and flowmeter data,
available from one of the boreholes, show that the derived
facies boundaries correlate with changes in grain size and
porosity, and to a lesser extent with changes in hydraulic
conductivity.[...]},
cin = {IBG-3},
cid = {I:(DE-Juel1)IBG-3-20101118},
pnm = {255 - Terrestrial Systems: From Observation to Prediction
(POF3-255)},
pid = {G:(DE-HGF)POF3-255},
typ = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
urn = {urn:nbn:de:0001-2017120719},
url = {https://juser.fz-juelich.de/record/834749},
}