Soils of the European Union - European Soil Portal - Europa

2. Materials and methods2.1 Soil Geographical Database of Eurasia at scale 1:1,000,000 (SGDBE)The Soil Geographical Database of Eurasia (SGDBE) has been used as the original source of information for our currentsoil mapping efforts.The Soil Geographical Database of Eurasia at scale 1:1,000,000 is part of the European Soil Information System (vanLiedekerke et al. 2004, Panagos 2006) and is the resulting product of a collaborative project involving soil surveyinstitutions and soil specialists in Europe and neighboring countries.The SGDBE consists of both a geometrical dataset and a semantic dataset (set of attribute files) which links attribute valuesto the polygons of the geometrical dataset. How map polygons, SMU's and STU's are linked together is illustrated in theFigure 1.The database contains a list of Soil Typological Units (STU). Besides the higher level soil taxonomic classification unitsrepresented by a soil name, these units are described by variables (attributes) specifying the nature and properties of thesoils: for example the texture, the water regime, the stoniness, etc. In our current soil mapping exercise we process the soiltaxonomic component (first level taxonomic classes: Reference Soil Groups; second level taxonomic classes: soil units,composed by RSGs and qualifiers) included in the STU.The geographical representation was chosen at a scale corresponding to the 1:1,000,000. At this scale, it is not feasible todelineate the STUs. Therefore they are grouped into Soil Mapping Units (SMU) to form soil associations and to illustratethe functioning of pedological systems within the landscapes. Each SMU corresponds to a part of the mapped territory andas such is represented by one or more polygons in a geometrical dataset. (Figure 2.1)Figure 2.1 Information organization in the Soil Geographical Database of Europe (EC 2003)4