Mapping Ground Water Vulnerability to Pesticide Leaching

Publication

To monitor the progress of the EU Thematic Strategy on the Sustainable Use of Pesticides, the Netherlands Environmental Assessment Agency (MNP) has developed a simple pesticide leaching indicator. This indicator was developed using results from a pan-European, process-based, numerical pesticide leaching model (EuroPEARL).

Abstract

A metamodel of the spatially distributed European pesticide leaching model EuroPEARL was developed. EuroPEARL considers transient flow and solute transport and assumes Freundlich adsorption, first-order degradation and passive plant-uptake of pesticides. Physical parameters are depth dependent while (bio)-chemical parameters are depth, temperature and moisture dependent. The metamodel is based on an analytical expression that describes the mass fraction of pesticide leached.

The metamodel ignores vertical pa-rameter variations and assumes steady flow. The calibration dataset was generated with EuroPEARL and consisted of approximately 60,000 simulations done for 56 pesticides with different half-lives and partitioning coefficients. The target variable was the 80th percentile of the annual average leaching concentration at 1 m depth from a time-series of 20 years. The metamodel explains over 90% of the variation of the original model with only four in-dependent spatial attributes. These parameters are available in European soil- and climate databases, so that the calibrated metamodel could be applied to generate maps of the pre-dicted leaching concentration in the European Union. Maps generated with the metamodel showed a good similarity with the maps obtained with EuroPEARL which was confirmed by means of quantitative performance indicators.

Authors

Tiktak, A, Boesten, JJTI, van der Linden, AMA, Vanclooster, M

Specifications

Publication title
Mapping Ground Water Vulnerability to Pesticide Leaching with a Process-Based Metamodel of EuroPEARL
Publication date
18 July 2006
Publication type
Publication
Magazine
Journal of Environmental Quality (35):1213-1226
Product number
91772