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| Titel |
Losses of glyphosate and AMPA via drainflow in a typical Belgian residential area |
| VerfasserIn |
Ting Tang, Wesley Boënne, Ann van Griensven, Piet Seuntjens, Jan Bronders, Nele Desmet |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250089425
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| Publikation (Nr.) |
 EGU/EGU2014-3627.pdf |
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| Zusammenfassung |
| Urban hard surfaces are considered as important facilitators for pesticide transport into urban
streams. To obtain concurrent high-resolution data for a detailed investigation on the losses of
pesticide runoff from hard surfaces, a monitoring campaign was performed in a typical
Belgian residential area (9.5 ha) between 7 May and 7 August, 2013. The campaign yielded a
concurrent dataset of rainfall (1-mm rainfall interval), discharge (1-min interval),
glyphosate application by the residents and the occurrences of glyphosate and its major
degradation product - aminomethylphosphonic acid (AMPA) in the separated storm
drainage outflow during 12 rainfall events. In addition, detailed information was
obtained on the spatial characteristics of the study area. The resulting dataset allows
us to investigate the relevance of catchment hydrology, urban surface properties
and pesticide application to the transport and losses of glyphosate in a residential
environment.
During the campaign, glyphosate was only applied by local residents, mainly on their
private driveways. As a result of their continuous use, both glyphosate and AMPA were
detected in all analysed outflow samples, with maximum concentrations of 6.1 μg/L and 5.8
μg/L, respectively. Overall, the storm drainage system collected 0.43% of the applied amount
of glyphosate. However, this loss rate varied considerably among rainfall events, ranging
from 0.04% to 23.36%. According to statistical analysis of the 12 rainfall events, the loss
rate was significantly correlated with three factors: the application amount prior to
a rainfall event (p < 0.005), rainfall amount during the event (p < 0.02) and the
weighted lag time between glyphosate application and the start of the rainfall event
(negatively, p < 0.05). A regression analysis showed that these three factors can explain
more than 85% of the variation in the loss rate of glyphosate. Furthermore, three
types of glyphosate runoff were classified by a clustering analysis based on these
factors: events dominated by runoff availability (runoff-limited), dominated by
glyphosate availability (pesticide-limited) and controlled by both runoff and glyphosate
availability. To sum up, proper management of the amount and timing of glyphosate
application can greatly help to control its losses from urban impervious surfaces. |
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