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| Titel |
Simulating pesticide transport in urbanized catchments: a new spatially-distributed dynamic pesticide runoff model |
| VerfasserIn |
Ting Tang, Piet Seuntjens, Ann van Griensven, Jan Bronders |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250127417
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| Publikation (Nr.) |
 EGU/EGU2016-7292.pdf |
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| Zusammenfassung |
| Urban areas can significantly contribute to pesticide contamination in surface water.
However, pesticide behaviours in urban areas, particularly on hard surfaces, are far less
studied than those in agricultural areas. Pesticide application on hard surfaces (e.g.
roadsides and walkways) is of particular concern due to the high imperviousness and
therefore high pesticide runoff potential. Experimental studies have shown that
pesticide behaviours on and interactions with hard surfaces are important factors
controlling the pesticide runoff potential, and therefore the magnitude and timing of peak
concentrations in surface water. We conceptualized pesticide behaviours on hard
surfaces and incorporated the conceptualization into a new pesticide runoff model.
The pesticide runoff model was implemented in a catchment hydrological model
WetSpa-Python (Water and Energy Transfer between Soil, Plants and Atmosphere, Python
version).
The conceptualization for pesticide processes on hard surfaces accounts for the
differences in pesticide behaviour on different hard surfaces. Four parameters are used to
describe the partitioning and wash-off of each pesticide on hard surfaces. We tested the
conceptualization using experimental dataset for five pesticides on two types of hard
surfaces, namely concrete and asphalt. The conceptualization gave good performance
in accounting for the wash-off pattern for the modelled pesticides and surfaces,
according to quantitative evaluations using the Nash-Sutcliffe efficiency and percent
bias.
The resulting pesticide runoff model WetSpa-PST (WetSpa for PeSTicides) can simulate
pesticides and their metabolites at the catchment scale. Overall, it includes four groups of
pesticide processes, namely pesticide application, pesticide interception by plant foliage,
pesticide processes on land surfaces (including partitioning, degradation and wash-off on
hard surface; partitioning, dissipation, infiltration and runoff in soil) and pesticide
processes in depression storage (including degradation, infiltration and runoff).
Processes on hard surfaces employs the conceptualization described in the paragraph
above.
The WetSpa-PST model can account for various spatial details of the urban features
in a catchment, such as asphalt, concrete and roof areas. The distributed feature
also allows users to input detailed pesticide application data of both non-point and
point origins. Thanks to the Python modelling framework prototype used in the
WetSpa-Python model, processes in the WetSpa-PST model can be simulated at
different time steps depending on data availability and the characteristic temporal scale
of each process. This helps to increase the computational accuracy during heavy
rainfall events, especially for the associated fast transport of pesticides into surface
water.
Overall, the WetSpa-PST model has good potential in predicting effects of management
options on pesticide releases from heavily urbanized catchments. |
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