Pesticide transport in groundwater at the national scale: coupling an unsaturated zone model with a groundwater flow model
Evaluation of the leaching potential of a pesticide and its metabolites is a crucial part of European registration procedures. So far, these procedures consider the movement into the shallow groundwater only. An important question is whether processes in the saturated zone can reduce the concentration in deeper aquifers to levels below a target value, for instance the drinking water limit. To investigate this problem, a spatially distributed model of pesticide leaching from soils was combined with a regional- scale groundwater flow and transport model.
The combined model was used to simulate the concentration of a commonly used mobile herbicide in deeper aquifers. Results indicate that the herbicide concentration in the shallow groundwater often exceeds the target value. Due to dispersion, concentrations generally decrease with depth, but the reduction in concentrations is not sufficient to lower the concentration below the drinking water limit of 0.1 µg L-1.
Authors
Specifications
- Publication title
- Pesticide transport in groundwater at the national scale: coupling an unsaturated zone model with a groundwater flow model
- Publication date
- 6 December 2005
- Publication type
- Publication
- Magazine
- In: Bringing groundwater quality research to the watershed scale. Proceedings of GQ2004, the 4th international groundwater quality conference, Waterloo, Canada, July, 2004. Wallingford: International Association of Hydrological Sciences, 2005;441-8 (IAHS publication 297)
- Product number
- 91650