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@PHDTHESIS{AlHazaimay:276116,
author = {Al-Hazaimay, Sadam},
title = {{U}sing the anisotropy of electrical properties for the
characterization of sedimentological structures and
preferential flow processes},
volume = {287},
school = {RWTH Aachen},
type = {Dissertation},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
reportid = {FZJ-2015-06593},
isbn = {978-3-95806-090-6},
series = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
Umwelt / Energy $\&$ Environment},
pages = {xxii, 94 S.},
year = {2015},
note = {Dissertation, RWTH Aachen, 2015},
abstract = {Detailed information about subsurface structures (e.g.
layering) and processes (e.g. ow and solute transport) in
the vadose zone is important for the characterizationand
protection of soil and groundwater. Unfortunately, such
informationis not easily accessible due to the complexity of
the soil system that exhibitsconsiderable spatial variation
in subsurface structure, which introduces signifi-cant
uncertainty when attempting to improve system understanding.
Because oflayering structures and macropores in the
subsurface, signiffcant changes in soilproperties appear in
horizontal and vertical directions that introduce
anisotropyin soil properties such as the hydraulic
conductivity and the electrical resistivity.The premise of
this thesis is that anisotropy in electrical resistivity can
be usedto extract meaningful information about other soil
characteristics and properties.In particular, we investigate
whether the anisotropy in electrical properties canbe used
to obtain information about the heterogeneity of sediment
structures andmacropore preferential ow processes using
non-invasive geophysical techniquesbecause such information
is hard to obtain in feld applications using
classicaldestructive methods. Synthetic modelling has shown
that information on soil heterogeneity can be obtainedfrom
the anisotropy in electrical resistivity. In particular, it
was shown thatthe correlation length ratio of bimodal facies
distribution of two isotropic materialswith different
complex resistivity can be inversely estimated from the
effectivecomplex electrical resistivity in two directions
(i.e. the anisotropy). In this thesis,this result from a
synthetic modelling study was experimentally validated
usingcomplex electrical resistivity measurements on a
measurement cell with two bimodalsediment distributions that
differ in the fraction and spatial arrangementof each
material. The effective complex electrical resistivity in
the mHz to kHz frequency range of these two sediment
distributions was determined using a novelanalysis approach.
To estimate the correlation length ratio, we used a global
optimization method that minimized the difference between
measured and modelled effective electrical resistivity.
Effective complex electrical resistivity measurementsof
heterogeneous distributions showed a good agreement with the
results obtained in the synthetic study for the same
distributions, although measurement results were very
sensitive to the sample thickness that was difficult to
control. It wasconcluded that the electrical anisotropy in
resistivity can indeed be used to obtain information about
the heterogeneity in sediments with a very high accuracy in
correlation length ratio, volume fraction, and the
electrical parameters of the Cole-Cole model.},
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:0001-2016022900},
url = {https://juser.fz-juelich.de/record/276116},
}