Soil property maps of Africa at 250 m
To access the updated maps of soil properties and classes please refer to: www.soilgrids.org
Over the period 2008–2014, the AfSIS project has compiled two soil profile data sets: the Africa Soil Profiles (legacy) database [Leenaars, 2014] and the AfSIS Sentinel Site (new soil samples) database [Vagen et al, 2010], jointly consisting of ca. 28 thousand sampling locations. Using these soil point observations and an extensive collection of global (SoilGrids1km) and local (African continent) environmental covariates, ISRIC - World Soil Information, in collaboration with The Earth Institute, Columbia University, World Agroforestry Centre, Nairobi and the International Center for Tropical Agriculture (CIAT), have produced (February 2015) predictions of soil properties — organic carbon, pH, sand, silt and clay fractions, coarse fragments, bulk density, cation-exchange capacity, total nitrogen, exchangeable acidity, Al content, and exchangeable bases (Ca, K, Mg, Na) — for the whole African continent at 250 m spatial resolution at two or six standard soil depths. The predictions are obtained using an automated mapping framework (3D regression-kriging based on random forests). Compressed GeoTiffs of the soil property maps, together with all metadata, input data sets and the R functions used to generate the maps, are available for download from here. A web-mapping interface to the maps is available via: http://af.soilgrids.org/. Read more about how were these maps made.
Distribution of soil sample locations in Africa used to build spatial predictive models: (left) legacy soil profile observations (Africa Soil Profiles database) showing ca. 18.5 thousand locations [Leenaars, 2014], and (right) AfSIS Sentinel Sites showing ca. 9.5 thousand locations, clustered at ca. 60 sentinel sites [Vagen et al, 2010]. Download point data in KMZ or rda format.
The AfSIS project has been funded by the Bill and Melinda Gates foundation and the Alliance for a Green Revolution in Africa (AGRA). To learn more about the AfSIS project, visit the project website Africasoils.net and/or the AGRA website. Please cite as:
- Hengl T, Heuvelink GBM, Kempen B, Leenaars JGB, Walsh MG, Shepherd KD, et al. (2015) Mapping Soil Properties of Africa at 250 m Resolution: Random Forests Significantly Improve Current Predictions. PLoS ONE 10(6): e0125814. doi:10.1371/journal.pone.0125814
This data set is available under the Attribution-NonCommercial International CC BY-NC. This means that: you are free to share (copy and redistribute the material in any medium or format) and adapt (remix, transform, and build upon the material), as long as you give appropriate credit and provide a link to the SoilGrids.org homepage; you may not use these materials for commercial purposes.
Inputs: Africa Soil Profile DB, AfSIS Sentinel Site database, Africa Soil covariates (250 m), SRTM DEM and derivatives (250 m), GlobLand30 land cover data (250 m), SoilGrids1km predictions.
Period (temporal coverage approximate): 1950–2012.
Spatial resolution (covariates): 250 m and 1 km.
Producers: ISRIC - World Soil Information, in collaboration with The Earth Institute, Columbia University World Agroforestry Centre, Nairobi and the International Center for Tropical Agriculture (CIAT)
Data license (IP policy): Attribution-NonCommercial International CC BY-NC
Size of each layer compressed: 50-500 MB (username: soilgrids / password: soilgrids).