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WRB reference soil group probability maps (SoilGrids 2.0)

ISRIC - World Soil Information

Part of: SoilGrids

Version2.0

Overview

Probability of occurrence of each of 30 World Reference Base (WRB 2006) reference soil groups, and the most probable group per cell, for the globe on a 250 m grid. These are the soil classification maps of SoilGrids 2.0, but they are not new predictions: ISRIC summed the qualifier-level class probabilities predicted in the SoilGrids250m 2017 release (multinomial neural network and random forest ensemble on about 150,000 WoSIS profiles) into one map per reference soil group, and took the highest as the most probable group. Anthrosols, Technosols and Retisols are not included. Each map is a GDAL virtual raster (VRT) that mosaics a folder of GeoTIFF tiles in place, so it opens remotely with GDAL-based tools.

Important note

The underlying model is the 2017 one, not the quantile regression forests of the SoilGrids 2.0 property maps, and ISRIC says a new unified soil classification method is under development. The files are in EPSG:4326 although the ISRIC catalogue record states Homolosine. The VRTs reference their tiles by relative path, so open them over HTTPS with GDAL's /vsicurl rather than downloading the .vrt alone, and read windows. Probabilities of the 30 groups in a cell do not always sum to exactly 100 because of rounding.

Intended uses

  • soil type inputs to crop, land evaluation, and ecosystem models at national to global scale
  • stratifying or masking analyses by dominant soil group

Not recommended for

field-scale soil identification

Why: values are 250 m predictions from the 2017 model with modest class accuracy, not survey observations.

Use instead: national soil survey maps or local profile descriptions.

Access & use

Files, endpoints, and worked examples for each distribution.

Data

probability

4096x4096 GeoTIFF tiles, one folder per reference soil group at {rsg}/.

Format: image/tiff

Variables: probability

Dimensions: cell × rsg

Data dictionary →

File indexes

GDAL VRThttps://files.isric.org/soilgrids/latest/data/wrb/{rsg}.vrt30 files

One VRT per reference soil group beside its tile folder, with a .vrt.ovr overview file

List of files 30 filesDownload CSV

Individual file

https://files.isric.org/soilgrids/latest/data/wrb/Acrisols.vrt

Usage examples

Python
import rioxarray

# The VRT opens as one raster; its tiles are read on demand
da = rioxarray.open_rasterio("https://files.isric.org/soilgrids/latest/data/wrb/Acrisols.vrt", masked=True)
Other access methods
HTTPS (WebDAV) directory:https://files.isric.org/soilgrids/latest/data/wrb/
most-probable

4096x4096 GeoTIFF tiles of the most probable group.

Format: image/tiff

Variables: MostProbable

Dimensions: cell

Data dictionary →

File indexes

GDAL VRThttps://files.isric.org/soilgrids/latest/data/wrb/MostProbable.vrt

VRT mosaicking the MostProbable tiles, with a .vrt.ovr overview file

Usage examples

Python
import rioxarray

# The VRT opens as one raster; its tiles are read on demand
da = rioxarray.open_rasterio("https://files.isric.org/soilgrids/latest/data/wrb/MostProbable.vrt", masked=True)
Other access methods
HTTPS (WebDAV) directory:https://files.isric.org/soilgrids/latest/data/wrb/MostProbable/

Additional assets

most-probable-legendmetadatadescribedby

Pixel value to reference soil group name for MostProbable.

Format: application/json

most-probable-stylevisual

SLD colour style for the MostProbable map.

Format: application/vnd.ogc.sld+xml

most-probable-previewoverview

Global rendering of the MostProbable map.

Format: image/png

wmsvisual

ISRIC WMS serving the WRB maps as rendered images.

Access the data

https://maps.isric.org/mapserv?map=/map/wrb.map

Data dictionary

What each file holds. A layout describes how the data is stored in a file: its variables, the dimensions they vary over, and any keys.

File layouts

FilesFormatVariablesDimensionsNo data
probabilityimage/tiffprobabilitycell × rsg255
most-probableimage/tiffMostProbablecell255

In every file

Dimensions

cellxy

7.5 arc-second cells (~250 m at the equator).

Grid spacing: 0.0020833333 degree

Only in probability

Variables

VariableTypeUnitDescription
probabilityuint8%Predicted probability that the cell's soil belongs to the reference soil group, in percent.

Dimensions

rsgsoil_group

WRB reference soil group, the {rsg} token of the file names (WRB 2006 names, so Albeluvisols rather than Retisols).

Type: string

Coded against: https://www.fao.org/soils-portal/data-hub/soil-classification/world-reference-base/en/

  • Acrisols
  • Albeluvisols
  • Alisols
  • Andosols
  • Arenosols
  • Calcisols
  • Cambisols
  • Chernozems
  • Cryosols
  • Durisols
  • Ferralsols
  • Fluvisols
  • Gleysols
  • Gypsisols
  • Histosols
  • Kastanozems
  • Leptosols
  • Lixisols
  • Luvisols
  • Nitisols
  • Phaeozems
  • Planosols
  • Plinthosols
  • Podzols
  • Regosols
  • Solonchaks
  • Solonetz
  • Stagnosols
  • Umbrisols
  • Vertisols
Show all 30 valuesShow fewer

Only in most-probable

Variables

VariableTypeDescription
MostProbableuint8Reference soil group with the highest predicted probability in the cell.
0
Acrisols
1
Albeluvisols
2
Alisols
3
Andosols
4
Arenosols
5
Calcisols
6
Cambisols
7
Chernozems
8
Cryosols
9
Durisols
10
Ferralsols
11
Fluvisols
12
Gleysols
13
Gypsisols
14
Histosols
15
Kastanozems
16
Leptosols
17
Lixisols
18
Luvisols
19
Nitisols
20
Phaeozems
21
Planosols
22
Plinthosols
23
Podzols
24
Regosols
25
Solonchaks
26
Solonetz
27
Stagnosols
28
Umbrisols
29
Vertisols

Technical metadata

The full spatial, temporal, and modeling detail behind the summaries elsewhere on this page.

Spatial

CRS
EPSG:4326
Extent (W S E N)
[-180, -56, 180, 84]
Coverage
World
Grid spacing
7.5 arc-seconds (~230 m at the equator)

Temporal

Reference date
2020

Provenance

Ordered processing steps, from source to publication.

  1. source2017-03-10

    SoilGrids250m 2017: ensemble of multinomial log-linear neural network (nnet) and random forest (ranger) models fitted on WoSIS soil profiles with WRB classes and global covariates, predicting per-class probabilities (Hengl et al. 2017).

    Derived from: WoSIS soil profile database ↗, SoilGrids250m 2017 TAXNWRB class probability layers ↗

  2. aggregate2020-05-04

    The 2017 qualifier-level probabilities summed into one map per reference soil group, and the group with the highest probability written as MostProbable. Published as part of SoilGrids 2.0.

  3. regenerate2022-03-01

    Layers regenerated with ISRIC's WRB mapping scripts to fix a distortion at low latitudes, and tiled as VRT mosaics.

    Code: wrb ↗

How to cite

Please cite the dataset and any associated peer-reviewed publications.

L. Poggio, L. M. de Sousa (2020-05-04) SoilGrids250m 2.0 - WRB classes and probabilities. Version 2.0. ISRIC - World Soil Information. https://doi.org/10.17027/isric-soilgrids.c4dc161c-d62d-11ea-a1a3-292680b15169. Accessed through the CGIAR Climate Action Data Hub, https://cgiar-climate-data-hub.github.io/catalog/soilgrids-wrb_2.0/.
BibTeX
BibTeX
@misc{soilgrids_wrb_2020,
  title     = {SoilGrids250m 2.0 - WRB classes and probabilities},
  author    = {Poggio, L. and de Sousa, L. M.},
  year      = {2020},
  version   = {2.0},
  publisher = {ISRIC - World Soil Information},
  doi       = {10.17027/isric-soilgrids.c4dc161c-d62d-11ea-a1a3-292680b15169},
  note      = {Accessed through the CGIAR Climate Action Data Hub, https://cgiar-climate-data-hub.github.io/catalog/soilgrids-wrb_2.0/}
}

Contacts

Who produced this dataset, and who to reach about it.

Brayden YoungbergMaintainer
Alliance of Bioversity International and CIAT
ISRIC - World Soil InformationLicensor
ProducerPoint of contact