Quantifying heterogeneous transport of a tracer and a degradable contaminant in the field, with snowmelt and irrigation
| Autor: | S.E.A.T.M. van der Zee, M.J. van der Ploeg, D. Schotanus |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Irrigation
well-structured soil nonequilibrium Water flow 0207 environmental engineering saturated soil Soil science 02 engineering and technology 010501 environmental sciences lcsh:Technology 01 natural sciences complex mixtures unsaturated zone lcsh:TD1-1066 law.invention law TRACER Vadose zone Leerstoelgroep Bodemnatuurkunde lcsh:Environmental technology. Sanitary engineering Leaching (agriculture) steady-state 020701 environmental engineering lcsh:Environmental sciences Filtration 0105 earth and related environmental sciences lcsh:GE1-350 WIMEK Macropore lcsh:T lcsh:Geography. Anthropology. Recreation 15. Life on land Leerstoelgroep Bodemnatuurkunde ecohydrologie en grondwaterbeheer Soil Physics ecohydrologie en grondwaterbeheer water-flow lcsh:G Snowmelt Ecohydrology and Groundwater Management solute transport propylene-glycol Soil Physics Ecohydrology and Groundwater Management spatial variability Geology preferential flow |
| Zdroj: | Hydrology and Earth System Sciences, 16, 2871-2882 Hydrology and Earth System Sciences, Vol 16, Iss 8, Pp 2871-2882 (2012) Hydrology and Earth System Sciences 16 (2012) |
| ISSN: | 1027-5606 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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