Pesticides Research No. 104 2006 – Establishment of a basis for administrative use of PestSurf

Establishment of a basis for administrative use of PestSurf

1 Background and Objectives

The Danish Environmental Protection Agency (DEPA) initiated in 1998 a project concerning development of a decision support system for administration of pesticides in relation to their effects on surface water. The decision support system for exposure was built around the models MIKE SHE and MIKE 11 and included a user interface and a number of scenarios for sandy and sandy loam conditions. The system is called PestSurf.

The experience with the use of PestSurf is limited and as data are available for whole catchments, there are numerous possibilites of extracting results at different scales and for different periods. This makes the system flexible, but not easily interpreted as an administrative tool. As an example, high concentrations may occur in small, almost dry ditches just after spraying, but this case may not represent the situation wanted as the basis for the administrative decision. The same situation is not found in other administrative tools, which are based on more standardised but hypothetical situations.

The objective of this project is to clarify the possibilities and limitations of the PestSurf system through calculation and analysis of concentrations for 12 pesticides. The reasons for pesticide occurrence and concentrations in different parts of the system and at different times is discussed. The PestSurf calculations are compared to similar calculations with the FOCUS Surface Water (FOCUS SW) tools, developed in an EU working group, and with the presently used practices. A procedure for data extraction and presentation has been established for the calculated scenarios and documented as examples of how simulation results could be handled in Annex 1-12. Suggestions for improvements of the data presentation and extraction tools are provided in Chapter ?5.

The project was carried out in close cooperation with the DEPA.