EUROPEAN SOIL BUREAU RESEARCH REPORT NO. 7 Quantitative approaches in harmonization of national soil maps

Compiling an international soil database from national soil databases is always difficult. The problems of edgematching, format and projection differences, translation and data value conversion often arise. The common way of dealing with these kinds of problems is the organization of harmonization meetings, where the experts from both sides get together to reach a common platform. Although, the geometric and attribute data format differences can be eliminated via this approach, the data inconsistency originated from the different approaches used for the contributing databases still limits the use of the data. Quantitative approaches of soil unit delineation can significantly decrease the spatial variability of the quality and reliability of the soil databases. Building quantitative soil spatial models and deriving the dependent soil variables from it requires quantitative, measured information from the scene. Collecting field data is one of the most crucial steps of every survey. It takes time and often represents the most expensive phase of the survey. On the other hand, there is a basic need for collecting more and more field data, because the overall performance of a geostatistics model depends largely on the density of the sampling points. A potential shortcut is the use of digital data sources, which represent a continuous surface representation, and provides data for the entire scene. Digital elevation models (DEM) and remotely sensed data are the mos