Siol map based Harmonized World Soil Database (v1.2)

Soil data is important both on a global scale and on a local scale, and due to the lack of reliable soil data, land degradation assessments, environmental impact studies, and sustainable land management interventions have received significant bottlenecks . Affected by the urgent need for soil information data around the world, especially in the context of the Climate Change Convention, the International Institute for Applied Systems Analysis (IIASA) and the Food and Agriculture Organization of the United Nations (FAO) and the Kyoto Protocol for Soil Carbon Measurement and FAO/International The Global Agroecological Assessment Study (GAEZ v3.0) jointly established the Harmonized World Soil Database version 1.2 (HWSD V1.2). Among them, the data source in China is the second national land in 1995. Investigate 1:1,000,000 soil data provided by Nanjing Soil. The resolution is 30 seconds (about 0.083 degrees, 1km). The soil classification system used is mainly FAO-90.

The core soil system unit unique verification identifier:

MU_GLOBAL-HWSD database soil mapping unit identifier, connected to the GIS layer.

MU_SOURCE1 and MU_SOURCE2 source database drawing unit identifiers

SEQ-soil unit sequence in the composition of the soil mapping unit;

The soil classification system utilizes the FAO-7 classification system or the FAO-90 classification system (SU_SYM74 resp. SU_SYM90) or FAO-85 (SU_SYM85).

The main fields of the soil property sheet include:

ID (database ID)

MU_GLOBAL (Soil Unit Identifier) ​​(Global)

SU_SYMBOL soil drawing unit

SU_SYM74 (FAO74 classification);

SU_SYM85 (FAO85 classification);

SU_SYM90 (name of soil in the FAO90 soil classification system);

SU_CODE soil charting unit code

SU_CODE74 soil unit name

SU_CODE85 soil unit name

SU_CODE90 soil unit name

DRAINAGE (19.5);

REF_DEPTH (soil reference depth);


AWC_CLASS (effective soil water content);

PHASE1: Real (soil phase);

PHASE2: String (soil phase);

ROOTS: String (depth classification to the bottom of the soil);

SWR: String (soil moisture content);

ADD_PROP: Real (specific soil type in the soil unit related to agricultural use);

T_TEXTURE (top soil texture);

T_GRAVEL: Real (top gravel volume percentage); (unit: %vol.)

T_SAND: Real (top sand content); (unit: % wt.)

T_SILT: Real (surface layer sand content); (unit: % wt.)

T_CLAY: Real (top clay content); (unit: % wt.)

T_USDA_TEX: Real (top layer USDA soil texture classification); (unit: name)

T_REF_BULK: Real (top soil bulk density); (unit: kg/dm3.)

T_OC: Real (top organic carbon content); (unit: % weight)

T_PH_H2O: Real (top pH) (unit: -log(H+))

T_CEC_CLAY: Real (cation exchange capacity of the top adhesive layer soil); (unit: cmol/kg)

T_CEC_SOIL: Real (cation exchange capacity of top soil) (unit: cmol/kg)

T_BS: Real (top level basic saturation); (unit: %)

T_TEB: Real (top exchangeable base); (unit: cmol/kg)

T_CACO3: Real (top carbonate or lime content) (unit: % weight)

T_CASO4: Real (top sulfate content); (unit: % weight)

T_ESP: Real (top exchangeable sodium salt); (unit: %)

T_ECE: Real (top conductivity). (Unit: dS/m)

S_GRAVEL: Real (bottom crushed stone volume percentage); (unit: %vol.)

S_SAND: Real (bottom sand content); (unit: % wt.)

S_SILT: Real (bottom sludge content); (unit: % wt.)

S_CLAY: Real (bottom clay content); (unit: % wt.)

S_USDA_TEX: Real (bottom USDA soil texture classification); (unit: name)

S_REF_BULK: Real (bottom soil bulk density); (unit: kg/dm3.)

S_OC: Real (underlying organic carbon content); (unit: % weight)

S_PH_H2O: Real (bottom pH) (unit: -log(H+))

S_CEC_CLAY: Real (cation exchange capacity of the underlying adhesive layer soil); (unit: cmol/kg)

S_CEC_SOIL: Real (cation exchange capacity of the bottom soil) (unit: cmol/kg)

S_BS: Real (underlying basic saturation); (unit: %)

S_TEB: Real (underlying exchangeable base); (unit: cmol/kg)

S_CACO3: Real (bottom carbonate or lime content) (unit: % weight)

S_CASO4: Real (bottom sulfate content); (unit: % weight)

S_ESP: Real (underlying exchangeable sodium salt); (unit: %)

S_ECE: Real (underlying conductivity). (Unit: dS/m)

The database is divided into two layers, with the top layer (T) soil thickness (0-30 cm) and the bottom layer (S) soil thickness (30-100 cm).

For other attribute values, please refer to the HWSD1.2_documentation documentation.pdf, The Harmonized World Soil Database (HWSD V1.2) Viewer-Chinese description and HWSD.mdb.

Data file naming and use method

Data in bil format, named hwsd.bil
Can be opened with remote sensing software and procedures

Required Data Citation View Data Cite Help About Data Citation
Cite as:

Meng Xianyong, Wang Hao. Siol map based Harmonized World Soil Database (v1.2). National Tibetan Plateau Data Center, 2018. (Download the reference: RIS | Bibtex )

Related Literatures:

1. Wieder, W.R., J. Boehnert, G.B. Bonan, and M. Langseth. 2014. Regridded Harmonized World Soil Database v1.2. Data set. Available on-line [] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA. .( View Details | Bibtex)

Using this data, the data citation is required to be referenced and the related literatures are suggested to be cited.

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To respect the intellectual property rights, protect the rights of data authors,expand servglacials of the data center, and evaluate the application potential of data, data users should clearly indicate the source of the data and the author of the data in the research results generated by using the data (including published papers, articles, data products, and unpublished research reports, data products and other results). For re-posting (second or multiple releases) data, the author must also indicate the source of the original data.

Example of acknowledgement statement is included below: The data set is provided by National Tibetan Plateau Data Center (

License: This work is licensed under an Attribution 4.0 International (CC BY 4.0)

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