 |
| Titel |
Quantifying heterogeneous transport of a tracer and a degradable contaminant in the field, with snowmelt and irrigation |
| VerfasserIn |
D. Schotanus, M. J. Ploeg, S. E. A. T. M. Zee |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 8 ; Nr. 16, no. 8 (2012-08-21), S.2871-2882 |
| Datensatznummer |
250013434
|
| Publikation (Nr.) |
 copernicus.org/hess-16-2871-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| To examine the persistence of preferential flow paths in a field
soil, and to compare the leaching of a degradable contaminant with
the leaching of a tracer, two field
experiments were performed using a multi-compartment sampler (MCS). The first experiment
was carried out during the snowmelt period in early spring, characterized
by high infiltration fluxes from snowmelt. The second experiment was
carried out in early summer with irrigation to mimic homogeneous
rainfall. During the second experiment, the soil was warmer and
degradation of the degradable contaminant was observed. For both
experiments, the highest tracer concentrations were found in the
same area of the sampler, but the leached tracer masses of the
individual locations were not highly correlated. Thus, the
preferential flow paths were stable between the two experiments. With a lower
infiltration rate, in the second experiment, more isolated peaks in
the drainage and the leached masses were found than in the first
experiment. Therefore, it is concluded that the soil heterogeneity is
mainly caused by local differences in the soil hydraulic properties,
and not by macropores. With higher infiltration rates, the high and low leaching cells were more clustered. The leached
masses of the degradable contaminant were lower than the leached
masses of the tracer, but the masses were highly
correlated. The first-order degradation rate and the dispersivity were fitted with CXTFIT; the first-order degradation rate was
0.02 d−1, and the dispersivity varied between 1.9 and
7.1 cm.
The persistence of the flow paths during the experiments suggests soil
heterogeneity as the driver for heterogeneous flow and solute transport in this soil.
At the MCS scale, heterogeneous snowmelt did not seem to have much influence on the
flow and solute paths. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|