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| Titel |
Uncertainties in pesticide monitoring using suction cups: Evidences from numerical simulations |
| VerfasserIn |
L. Weihermüller, R. Kasteel, J. Vanderborght, J. Šimůnek, H. Vereecken |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250020500
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| Zusammenfassung |
| Risk assessment of pesticide leaching towards the groundwater becomes more and more
prescribed by the authorities. Various methods are available to monitor transport and leaching
of pesticides in the vadose zone. For experiments at the field scale, soil coring or in-situ
sampling using capillary wicks, porous plates, and suction cups are used. The advantage of
the in-situ sampling systems resides in the high temporal resolution of solute extraction at
different depths or horizons. Especially suction cups seem to play an important role in
pesticide monitoring due to their easy installation and low costs. In literature, most studies
analyzing suction cup behavior focused on conservative substances, steady state infiltration,
and homogeneous soils. In our numerical study, we analyzed breakthrough curves from
suction cups in heterogeneous soils under atmospheric conditions. To account for reactive
transport, two pesticides were also simulated, whereby each one represents a different
physico-chemical behavior. Finally, we simulated two different operation modes of the
suction cups: i) permanent suction according to a measured reference tensiometer
plus additional offset, and ii) weekly operation with constant suction of -600 cm.
The results show that the breakthrough as well as the mass recovery and the mean
concentration depends on the physico-chemical properties of the substance and location
of the suction cup within the heterogeneous flow field. Second, the total mass as
well as the mean concentration depends on the operation mode of the suction cup
system. |
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