Experiences and challenges in developing European soil hydrological databases

Development of the Hydraulic Properties of European Soils (HYPRES) database began in 1995 and was funded by the European Commission. The main aims of the project were to collate existing soil hydrological data held by Universities and Research Institutes into a single database and to use these data to derive a set of pedotransfer functions to predict soil hydrological properties for use in simulation models. Data were collated from 21 partners from 20 different Institutions throughout Europe encompassing 12 different countries. The database was structured around six main tables comprising two with either profile or horizon specific contextual data, three with ‘raw’ data and one with a suite of derived, standardized soil hydrological properties.

A recent review of the HYPRES database revealed some errors that were not identified during previous extensive checks and highlighted a number of decisions that, with hindsight, were not ideal. The database was subsequently revised such that an additional table with units was added, hierarchical approaches to describing land use and parent material were adopted, soil classification was standardized and the data in some fields were simplified.

HYPRES was a highly successful project and the derived pedotransfer functions have been widely used. However, some of the key lessons learnt from developing the database were: ensure there is agreement from all contributors that the data can be used freely by other researchers and establish plans for the long term management and upkeep of the database.