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| Titel |
Hydrodynamic dispersion characteristics of lateral inflow into a river tested by a laboratory model |
| VerfasserIn |
P. Y. Chou, G. Wyseure |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 13, no. 2 ; Nr. 13, no. 2 (2009-02-23), S.217-228 |
| Datensatznummer |
250011763
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| Publikation (Nr.) |
 copernicus.org/hess-13-217-2009.pdf |
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| Zusammenfassung |
Groundwater and river-water have a different composition and interact in and
below the riverbed. The riverbed-aquifer flux interactions have received
growing interest because of their role in the exchange and transformation of
nutrients and pollutants between rivers and the aquifer. In this research
our main purpose is to identify the physical processes and characteristics
needed for a numerical transport model, which includes the unsaturated
recharge zone, the aquifer and the riverbed. In order to investigate such
lateral groundwater inflow process, a laboratory J-shaped column experiment
was designed. This study determined the transport parameters of the J-shaped
column by fitting an analytical solution of the convective-dispersion
equation for every flux on individual segments to the observed breakthrough
curves of the resident concentration, and by inverse modelling for every
flux simultaneously over the entire flow domain. The obtained
transport-parameter relation was tested by numerical simulation using HYDRUS
2-D/3-D.
Four steady-state flux conditions (i.e. 0.5 cm hr−1, 1 cm hr−1,
1.5 cm hr−1 and 2 cm hr−1) were applied,
transport parameters including pore water velocity and dispersivity were
determined for both unsaturated and saturated sections along the column.
Results showed that under saturated conditions the dispersivity was fairly
constant and independent of the flux. In contrast, dispersivity under
unsaturated conditions was flux dependent and increased at lower flux. For
our porous medium the dispersion coefficient related best to the quotient of
the pore water velocity divided by the water content. A simulation model of
riverbed-aquifer flux interaction should take this into account. |
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