ISRIC Report 2015/03: Towards the standardization and harmonization of world soil data: Procedures Manual ISRIC World Soil Information Service (WoSIS ver. 2.0)

isric_report_2015_03.pdf (pdf, 3.87 MB)
Year of publication
Ribeiro, Eloi
Batjes, Niels H.
Leenaars, J.G.B
Van Ooostrum, Ad
Mendes de Jesus, J.
Note: Latest version was published in 2020.

To better address the growing demand for soil information ISRIC - World Soil Information has developed a centralized and user-focused database for the shared benefit of the international community. This relational database, referred to as World Soil Information Service (WoSIS), will only serve quality-assessed and authorized data with detailed information on data lineage. Such information may be used to address pressing challenges of our time including food security, land degradation, water resources, and climate change.

Following the release of WoSIS version 1.0 in 2013, several needs for modification were identified by the user community. The consolidated feedback led to a revised version, WoSIS 2, which has been designed in such a way that, in principle, any type of soil data (point, polygon, and grid) can be accommodated. Basic principles for this are described in this report.

Seen the magnitude of the task, the initial focus has been on processing disparate soil profile data sets obtained from various data providers. These data sets are imported ‘as is’ into a PostgreSQL database, with the original naming and coding conventions, abbreviations, domains, lineage and data licence; thereby copies of the source materials are safeguarded at ISRIC.

Next the source databases are imported into WoSIS, forming the first major step of data standardization (into a single data model). The second step of data standardization, applied to the values for the various soil properties as well as to the naming conventions, is needed to make the data queryable and useable. Special attention has been paid here to the standardization of analytical method descriptions, in first instance focusing on the list of soil attributes considered in the GlobalSoilMap specifications (e.g. organic carbon, soil pH, soil texture (sand, silt, and clay), coarse fragments (< 2mm), cation exchange capacity, bulk density, and water holding capacity). Major characteristics of commonly used methods for determining a given soil property are identified first. For soil pH, for example, these are the extractant solution (water or salt solution), and in case of salt solutions the salt concentration (molarity), as well as the soil/solution ratio; a further descriptive element is the type of instrument used for the actual laboratory measurement. The standardized procedures developed so far have been applied to the ‘shared’ profile data, forming the first set of ‘standardized’ data generated from WoSIS. A possible third step in the standardization/harmonization process, not yet undertaken in this version of WoSIS, will require data harmonization to make the data comparable that is as if assessed by a single given (reference) method. Such work will require further international collaboration and data sharing to the benefit of the international user community.

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