基于世界土壤数据库（HWSD）土壤数据集

无论从全球尺度亦或是局地尺度而言，土壤数据及其重要，而由于缺乏可靠的土壤数据，土地退化评估、环境影响研究和、可持续的土地管理干预措施收到了极大的瓶颈阻碍。受到土壤信息数据在全世界的迫切需要，特别是在气候变化公约的背景下，国际应用系统分析研究所（IIASA）及联合国粮农组织（FAO）和京都协议对土壤碳测量和联合国粮农组织/国际全球农业生态评价研究(GAEZ v3.0)共同倡导下建立了新一代世界土壤数据库(Harmonized World Soil Database version 1.2 )(HWSD V1.2).其中，中国地区数据源为1995年全国第二次土地调查由南京土壤所所提供的1:1,000,000土壤数据。数据格式:grid栅格格式，投影为WGS84。采用的土壤分类系统主要为FAO-90。
核心土壤制度单元唯一验证标识符：
MU_GLOBAL-HWSD数据库土壤制图单元标示符，连接了GIS图层。
MU_SOURCE1 和 MU_SOURCE2- 源数据库制图单元标识符
SEQ-土壤制图单元组成中的土壤单元序列；
土壤分类系统利用FAO-7分类系统或 FAO-90分类系统(SU_SYM74 resp. SU_SYM90)或FAO-85(SU_SYM85).

土壤属性表主要字段包括:
ID(数据库ID)
MU_GLOBAL(土壤单元标识符)（全球）
SU_SYMBOL 土壤制图单元
SU_SYM74(FAO74分类);
SU_SYM85(FAO85分类);
SU_SYM90（FAO90土壤分类系统中土壤名称)；
SU_CODE 土壤制图单元代码
SU_CODE74 土壤单元名称
SU_CODE85 土壤单元名称
SU_CODE90 土壤单元名称
DRAINAGE(19.5);
REF_DEPTH(土壤参考深度);
AWC_CLASS(19.5);
AWC_CLASS(土壤有效水含量);
PHASE1: Real (土壤相位);
PHASE2: String (土壤相位)；
ROOTS: String (到土壤底部存在障碍的深度分类)；
SWR: String (土壤含水量特征)；
ADD_PROP: Real (土壤单元中与农业用途有关的特定土壤类型)；

T_TEXTURE(顶层土壤质地);
T_GRAVEL: Real (顶层碎石体积百分比)；(单位：%vol.)
T_SAND: Real (顶层沙含量)； (单位：% wt.)
T_SILT: Real (表层粉沙粒含量)； (单位：% wt.)
T_CLAY: Real (顶层粘土含量)； (单位：% wt.)
T_USDA_TEX: Real (顶层USDA土壤质地分类)； (单位：name)
T_REF_BULK: Real (顶层土壤容重)； (单位：kg/dm3.)
T_OC: Real (顶层有机碳含量)； (单位：% weight)
T_PH_H2O: Real (顶层酸碱度) (单位：-log(H+))
T_CEC_CLAY: Real (顶层粘性层土壤的阳离子交换能力)； (单位：cmol/kg)
T_CEC_SOIL: Real (顶层土壤的阳离子交换能力) (单位：cmol/kg)
T_BS: Real (顶层基本饱和度)； (单位：%)
T_TEB: Real (顶层交换性盐基)；(单位：cmol/kg)
T_CACO3: Real (顶层碳酸盐或石灰含量) (单位：% weight)
T_CASO4: Real (顶层硫酸盐含量)；(单位：% weight)
T_ESP: Real (顶层可交换钠盐)；(单位：%)
T_ECE: Real (顶层电导率)。 (单位：dS/m)
S_GRAVEL: Real (底层碎石体积百分比)；(单位：%vol.)
S_SAND: Real (底层沙含量)； (单位：% wt.)
S_SILT: Real (底层淤泥含量)； (单位：% wt.)
S_CLAY: Real (底层粘土含量)； (单位：% wt.)
S_USDA_TEX: Real (底层USDA土壤质地分类)； (单位：name)
S_REF_BULK: Real (底层土壤容重)； (单位：kg/dm3.)
S_OC: Real (底层有机碳含量)； (单位：% weight)
S_PH_H2O: Real (底层酸碱度) (单位：-log(H+))
S_CEC_CLAY: Real (底层粘性层土壤的阳离子交换能力)； (单位：cmol/kg)
S_CEC_SOIL: Real (底层土壤的阳离子交换能力) (单位：cmol/kg)
S_BS: Real (底层基本饱和度)； (单位：%)
S_TEB: Real (底层交换性盐基)；(单位：cmol/kg)
S_CACO3: Real (底层碳酸盐或石灰含量) (单位：% weight)
S_CASO4: Real (底层硫酸盐含量)；(单位：% weight)
S_ESP: Real (底层可交换钠盐)；(单位：%)
S_ECE: Real (底层电导率)。 (单位：dS/m)

本数据库分两层，其中以顶层（T）土壤厚度为（0-30cm），底层（S）土壤厚度为（30-100cm）。
其他属性值请参考说明HWSD1.2_documentation文档.pdf，The Harmonized World Soil Database (HWSD V1.2) Viewer-中文说明及HWSD.mdb。

Soil data are extremely important at both global and local scales. However, the lack of reliable soil data has posed severe bottlenecks and hindrances to land degradation assessments, environmental impact studies, and sustainable land management interventions. Amid the urgent global demand for soil information, particularly in the context of the United Nations Framework Convention on Climate Change, the Harmonized World Soil Database version 1.2 (HWSD V1.2), a new-generation global soil database, was jointly initiated by the International Institute for Applied Systems Analysis (IIASA), the Food and Agriculture Organization of the United Nations (FAO), the soil carbon measurement initiative under the Kyoto Protocol, and the FAO/Global Agro-Ecological Zones (GAEZ v3.0) research program.

For the Chinese region, the data source is the 1:1,000,000-scale soil survey data provided by the Nanjing Institute of Soil Science during the Second National Land Survey in 1995. The data are stored in grid raster format with WGS84 projection, and the main soil classification system adopted is FAO-90.

### Unique Verifying Identifiers for Core Soil Mapping Units
MU_GLOBAL: Soil mapping unit identifier of the HWSD database, linked to GIS layers.
MU_SOURCE1 and MU_SOURCE2: Source database mapping unit identifiers.
SEQ: Sequence of soil units within a soil mapping unit.
The soil classification systems used include the FAO-7 classification, FAO-90 classification (SU_SYM74 resp. SU_SYM90), and FAO-85 classification (SU_SYM85).

### Main Fields of the Soil Attribute Table
ID: Database ID
MU_GLOBAL: Global soil unit identifier
SU_SYMBOL: Soil mapping unit
SU_SYM74: FAO 74 classification
SU_SYM85: FAO 85 classification
SU_SYM90: Soil name in the FAO 90 soil classification system
SU_CODE: Soil mapping 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(19.5)
AWC_CLASS: Soil available water content
PHASE1: Real (Soil phase)
PHASE2: String (Soil phase)
ROOTS: String (Depth classification with impediments to soil bottom penetration)
SWR: String (Soil water content characteristics)
ADD_PROP: Real (Specific soil types related to agricultural use in the soil unit)

#### Topsoil (T Layer) Attributes
T_TEXTURE: Topsoil texture
T_GRAVEL: Real (Volume percentage of topsoil gravel; unit: %vol.)
T_SAND: Real (Topsoil sand content; unit: % wt.)
T_SILT: Real (Topsoil silt content; unit: % wt.)
T_CLAY: Real (Topsoil clay content; unit: % wt.)
T_USDA_TEX: Real (Topsoil USDA soil texture classification; unit: name)
T_REF_BULK: Real (Topsoil bulk density; unit: kg/dm³)
T_OC: Real (Topsoil organic carbon content; unit: % weight)
T_PH_H2O: Real (Topsoil pH; unit: -log(H+))
T_CEC_CLAY: Real (Cation exchange capacity of topsoil clay layer; unit: cmol/kg)
T_CEC_SOIL: Real (Cation exchange capacity of topsoil; unit: cmol/kg)
T_BS: Real (Topsoil base saturation; unit: %)
T_TEB: Real (Topsoil exchangeable bases; unit: cmol/kg)
T_CACO3: Real (Topsoil carbonate or lime content; unit: % weight)
T_CASO4: Real (Topsoil sulfate content; unit: % weight)
T_ESP: Real (Topsoil exchangeable sodium percentage; unit: %)
T_ECE: Real (Topsoil electrical conductivity; unit: dS/m)

#### Subsoil (S Layer) Attributes
S_GRAVEL: Real (Volume percentage of subsoil gravel; unit: %vol.)
S_SAND: Real (Subsoil sand content; unit: % wt.)
S_SILT: Real (Subsoil silt content; unit: % wt.)
S_CLAY: Real (Subsoil clay content; unit: % wt.)
S_USDA_TEX: Real (Subsoil USDA soil texture classification; unit: name)
S_REF_BULK: Real (Subsoil bulk density; unit: kg/dm³)
S_OC: Real (Subsoil organic carbon content; unit: % weight)
S_PH_H2O: Real (Subsoil pH; unit: -log(H+))
S_CEC_CLAY: Real (Cation exchange capacity of subsoil clay layer; unit: cmol/kg)
S_CEC_SOIL: Real (Cation exchange capacity of subsoil; unit: cmol/kg)
S_BS: Real (Subsoil base saturation; unit: %)
S_TEB: Real (Subsoil exchangeable bases; unit: cmol/kg)
S_CACO3: Real (Subsoil carbonate or lime content; unit: % weight)
S_CASO4: Real (Subsoil sulfate content; unit: % weight)
S_ESP: Real (Subsoil exchangeable sodium percentage; unit: %)
S_ECE: Real (Subsoil electrical conductivity; unit: dS/m)

This database is divided into two layers: the top layer (T) has a soil thickness of 0-30 cm, and the bottom layer (S) has a soil thickness of 30-100 cm.

For additional attribute values, please refer to the document HWSD1.2_documentation.pdf, the Chinese instruction manual of *The Harmonized World Soil Database (HWSD V1.2) Viewer*, and HWSD.mdb.

搜集汇总

背景与挑战

背景概述

该数据集基于Harmonized World Soil Database (HWSD) version 1.2，是一个全球尺度的土壤数据库，由国际应用系统分析研究所（IIASA）和联合国粮农组织（FAO）等机构共同建立，旨在提供可靠的土壤信息以支持土地退化评估、气候变化研究和可持续土地管理。数据集覆盖全球范围（东经180度至西经180度，南纬60度至北纬90度），时间范围为1995年，数据格式为grid栅格格式（WGS84投影），包含详细的土壤属性如土壤质地、有机碳含量和酸碱度等，分为顶层和底层两层，数据大小为1.78 GB，共享方式为开放获取。