Soil Profile analytical database for Europe (SPADE): Reconstruction and validation of the measured data (SPADE/M)
Résumé
The Soil Profile Analytical Database of Europe of Measured profiles (SPADE/M) was created to provide a common structure for storing harmonized information on typical soil profile properties of European soils. The main difficulty encountered in constructing the database was the transfer of the source data from individual electronic spreadsheet pages to the more rigid structure of a relational database. The data in spreadsheet format had been collected more than 12 years earlier but pressure was mounting for the capability to link these data to the Soil Map of Europe. A semi-automatic process was implemented to transfer data from nominal positions on the spreadsheet page to an intermediate structure highlighting any deviations from expected values. Conflicting situations were solved by manual intervention and expert judgement. Data in the intermediate structure were subjected to a validation procedure with the aim of storing uniform data in the database. The validation checks cover format authentication, restricting entries to permissible values and those passing plausibility tests. In cases where a horizon property could not be represented consistently following the field specifications, the database structure was adapted to accommodate those conditions. The database model was extended to allow data from multiple samples taken at the same plot and from the analysis of samples from different laboratories to be stored.