FAQ - WoSIS
- What is WoSIS?
- Which soil properties are standardised in WoSIS?
- What do the attribute codes mean?
- What measures of accuracy are provided?
- How can I access data derived from WoSIS?
- What is the WoSIS data-sharing policy?
- How can I help improve WoSIS and SoilGrids?
- Who provided soil profile data for the WoSIS effort?
- What if I could not find an answer to my question?
- Cited sources
WoSIS stands for 'World Soil Information Service', a large PostgreSQL database developed and maintained by ISRIC, WDC-Soils. It provides a growing range of quality-assessed and standardised soil profile data for the world. For this, it draws on voluntary contributions of data holders/providers worldwide.
The quality-assessed and standardised data are made available freely to the international community through several webservices, this in compliance with the conditions (licences) specified by the various data providers.
For additional details about WoSIS please click here.
We presently standardise the following soil chemical properties (organic carbon, total carbon, total carbonate equivalent, total nitrogen, phosphorus (extractable-P, total-P, and P-retention), soil pH, cation exchange capacity, and electrical conductivity) and physical properties (soil texture (sand, silt, and clay), bulk density, coarse fragments, and water retention), grouped according to analytical procedures (aggregates) that are operationally comparable.
Further, for each profile, we provide the original soil classification (FAO, WRB, USDA, and version) and horizon designations insofar as these have been specified in the source databases.
Measures for geographical accuracy (i.e. location) of the point data as well as a first approximation for the uncertainty associated with the operationally-defined analytical methods and date of description/sampling are presented, for possible consideration in digital soil mapping and subsequent earth system modelling.
For a detailed description of procedures see here.
File naming conventions, descriptions and units of measurement used in the latest release of WoSIS (i.e. 'wosis_latest') are detailed here.
We provide three measures for the (inferred) accuracy for the standardised data:
- Geographic accuracy (expressed as approximate precision in meter).
- Attribute accuracy (variability, expressed as coefficient of variation).
- Age of data (date the profiles were described/sampled).
The above measures may be considered when calculating the accuracy of digital soil maps and of any interpretations derived from them. Further information is provided in the following data paper.
Standardised datasets derived from WoSIS are distributed in two ways. The most recent, latest (dynamic) version can be accessed through an OGC-compliant WFS (Web Feature Service). Further, snapshot (static) dataset(s) in TSV (tab separated values) format with a DOI are provided for consistent citation purposes.
The most recent WoSIS release can be accessed through the following services:
WoSIS_latest: This dynamic dataset contains the most recent complement of standardised soil data served from WoSIS. Being dynamic, this dataset will grow once new point data are standardised, additional soil properties are considered, and/or when possible ammendments are required. The data can be accessed through an OGC-compliant WFS (Web Feature Service); for this, enter the following WFS link (http://maps.isric.org/mapserv?map=/map/wosis_latest.map) directly in your GIS application. For an overview of layers served, please go to the ISRIC Soil Data Hub and enter 'wosis_latest' as search term.
- Snapshots: These static datasets, in TSV format, are a representation of the complement of standardised data available at a given moment. Each snapshot is given a unique name and digital object identifier (DOI) for consistent citation purposes. Presently, two snapshots are provided: 'July-2016' and 'September-2019'. Generally, a new snapshot will be prepared when some 40,000-80,000 new profiles have been shared with us for standardisation and/or the range of soil properties standardised has increased substantially.
- Accessing 'wosis_latest' from QGIS, see Procedures Manual (App. A).
- Accessing wosis-data form R, see tutorial by David Rossiter.
Standardised data provided through WoSIS are freely accessible, provided the source of the standardised data is duly acknowledged.
The data licence specified by the various data providers is indicated in the database itself; this may be CC BY or CC BY NC. Datasets with a more restrictive CC-licence are not served through WoSIS, yet some of these may be used for SoilGrids applications based on a more specific licence agreement.
Overall, data are provided to users under the general terms and conditions of the ISRIC software and data policy.
To improve SoilGrids predictions for your country or region, please consider contributing soil profile data for standardisation in WoSIS. Note that ISRIC will always respect the data policy of the data provider and will not publically share any data unless written permission is given to us to do so. Agencies that contribute data are acknowledged as a contributing organisation on our website.
WoSIS draws on a large collection of geo-referenced soil profile data for the world. Populating WoSIS has been made possible thanks to the contributions and shared knowledge of a steadily growing number of data providers; we gratefully acknowledge their contributions.
If you have a technical question about WoSIS that is yet not answered in this FAQ, please post it to our 'Google group'. For this, please register first at WoSIS user group. ISRIC staff will be automatically notified of any new questions arising. Using the group will make it easier for other WoSIS-users to find quality answers to their questions.
WoSIS is funded from ISRIC's core funding (Netherlands Government).
A wide range of agencies and experts have provided data for the WoSIS/SoilGrids effort; we gratefully thank them for their contributions.
- Batjes NH, Ribeiro E, van Oostrum A, Leenaars J, Hengl T and Mendes de Jesus J (2017). WoSIS: providing standardised soil profile data for the world. Earth Syst. Sci. Data 9, 1-14. doi:10.5194/essd-9-1-2017
- Batjes NH, Ribeiro E, van Oostrum A and van den Bosch R (2018). Towards efficient workflows for soil data standardisation and model integration. Soils as a sustainable resource. BONARES Conference 2018, Berlin (26-28 Febrauary 2018) PDF
- Batjes N.H., Ribeiro E, and van Oostrum Ad (2020). Standardised soil profile data to support global mapping and modelling (WoSIS snapshot 2019). Earth System Science Data doi: 10.5194/essd-12-299-2020
- Ribeiro E, Batjes NH and van Oostrum AJM 2018. World Soil Information Service (WoSIS) - Towards the standardization and harmonization of world soil data. Procedures Manual 2018. ISRIC Report 2018/01, ISRIC - World Soil Information, Wageningen, 166 p. doi: 10.17027/isric-wdcsoils.20180001