Applied numerical modeling of saturated / unsaturated flow and ...

C/C 0 [-]
C/C 0 [-]
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
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0.001
cambisol (dil.)
podzol (dil.)
chernozem (dil.)
cambisol
podzol
chernozem
0 50 100 150 200 250
time [a]
a) naphthalene b) phenanthrene
c) naphthalene
with degradation
d) phenanthrene
with degradation
0 50 100 150 200 250
time [a]
Fig. 17: Concentration breakthrough curves at the groundwater surface below the road dam
for three different subsoil types showing naphthalene without (a) and with degradation (c),
and phenanthrene without (b) and with degradation (d) (Beyer et al., 2007b [EP 6]).
The results allow important conclusions on
mechanisms (e.g. capillary barrier effects)
and complementary design criteria for road
constructions, which can be used to reduce
contaminant leaching to groundwater.
4. Conclusions and outlook
In this thesis, the utilization of process
based numerical models of saturated / unsaturated
flow and reactive contaminant transport
is demonstrated for two different fields
of application.
The Virtual Aquifer (VA) concept is
introduced, which uses numerical modeling
as a tool for the computer based evaluation
of investigation and remediation strategies
for contaminated soils and aquifers. In the
application examples presented, the VA
concept proves its usefulness for assessing
the uncertainty involved in the investigation
of heterogeneous sites and the parameterization
of degradation process models.
Moreover, the VA concept is successfully
applied to test a newly developed approach
for the inference of biodegradation parameters
from data typically collected during site
investigation. Both applications exemplify
the importance but also the pitfalls of a
careful and accurate collection of investigation
data, if these are to be used for
prognosis of the contaminant behaviour at a
site. The main advantage of the VA is, that
individual factors, such as hydraulic heterogeneity
or conceptual model errors can be
studied in detail at low costs and without
high effort, either individually or in combination
and under otherwise ideal and
controlled conditions. As the sum of these
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