34
P. Cepuder and V. aus-der-Schmitten
the Marchfeld Plain with regard to percolation and nitrogen leaching. The study
was to evaluate scenarios of alternative land use in the pannonic region and help
finding areas of afforestation, as the region is underforested with 15% wood,
placed mainly outside the area.
Due to the large area of investigation, mathematical simulation models have
been used to estimate effects of alternative land use on water resources,
additionally to on-going field investigations. Nitrogen leaching is calculated with
EPIC (environmental policy integrated climate), which is a physically based fieldscale model for continuous simulation. It can be used to determine the effect of
management strategies on agricultural production, soil, and water resources.
Empiric formula have been used to calculate soil parameters needed for the
simulations, as these parameters are not available for larger areas.
A GIS application provides tools for database and visualization; also the EPIC
model can be accessed from this user interface within the GIS.
2 Materials and Methods
2.1 Database
To work with EPIC, some basic data are needed, such as information on soil,
weather, and crop rotation in the investigated area.
2.1.1 Soil
The Austrian Soil Map (OBK 1976) serves as the basis for all soil data. It has been
digitized for the investigation area, the Marchfeld Plain (Fig. 1), and includes a
polygon map (Fig. 2) with an attribute table for the soil parameters for all soil
layers up to 100 cm. For the EPIC simulation, the following parameters were
used: layer depth, soil texture, organic matter, coarse content, calcium matter,
density, and pH value.
The spatial use of point soil parameters for larger areas was verified in a field
study: the spatial empirical variance was shown in a sernivariogramrn (Phillip
2000) and the approach was found to be applicable to the given problem.
The single soil type represented as a polygon in Fig. 2 is the basic unit of all
calculations with the simulation model. The simulation is run once for each soil
type and each crop rotation.
P. Cepuder and V. aus-der-Schmitten
the Marchfeld Plain with regard to percolation and nitrogen leaching. The study
was to evaluate scenarios of alternative land use in the pannonic region and help
finding areas of afforestation, as the region is underforested with 15% wood,
placed mainly outside the area.
Due to the large area of investigation, mathematical simulation models have
been used to estimate effects of alternative land use on water resources,
additionally to on-going field investigations. Nitrogen leaching is calculated with
EPIC (environmental policy integrated climate), which is a physically based fieldscale model for continuous simulation. It can be used to determine the effect of
management strategies on agricultural production, soil, and water resources.
Empiric formula have been used to calculate soil parameters needed for the
simulations, as these parameters are not available for larger areas.
A GIS application provides tools for database and visualization; also the EPIC
model can be accessed from this user interface within the GIS.
2 Materials and Methods
2.1 Database
To work with EPIC, some basic data are needed, such as information on soil,
weather, and crop rotation in the investigated area.
2.1.1 Soil
The Austrian Soil Map (OBK 1976) serves as the basis for all soil data. It has been
digitized for the investigation area, the Marchfeld Plain (Fig. 1), and includes a
polygon map (Fig. 2) with an attribute table for the soil parameters for all soil
layers up to 100 cm. For the EPIC simulation, the following parameters were
used: layer depth, soil texture, organic matter, coarse content, calcium matter,
density, and pH value.
The spatial use of point soil parameters for larger areas was verified in a field
study: the spatial empirical variance was shown in a sernivariogramrn (Phillip
2000) and the approach was found to be applicable to the given problem.
The single soil type represented as a polygon in Fig. 2 is the basic unit of all
calculations with the simulation model. The simulation is run once for each soil
type and each crop rotation.