1. What is GeoPEARL?
GeoPEARL is a spatially-distributed model of pesticide leaching to the groundwater and surface waters in the Netherlands.
Calculations are performed for 1D-columns
During the parameterisation of the model, information from a regional groundwater flow model was used so that it is possible to distinguish between fluxes into the groundwater and fluxes into surface waters (next slide).

2. Position of PEARL column in landscape
field- ditches
water courses < 3m
water courses > 3 m
PEARL 1D
column
Leaching into the
regional
groundwater
Groundwater
table
Drainage into local
surface waters

3. The plot approach
PEARL is run in a GIS context for a large number of unique combinations (plots) of soil, climate, land-use and hydrogeological units.

4. Derivation of the unique combinations:
GeoPEARL is a spatially-distributed model of pesticide leaching to the groundwater and surface waters in the Netherlands
The core of the model consists of a 1D-model, i.e. FOCUS PEARL
PEARL is run in a GIS context for a large number of unique combinations (plots) of soil, climate, land-use and hydrogeological units.
A Graphical User Interface facilitates model use.

5. Plots are represented by a single vertical column:
A plot

6. Basic soil properties in GeoPEARL
Clay soils with near neutral pH-values (‘lower part’)
Acidic peat soils
Slightly acidic
sandy soils (‘higher part’)