1 Scope
This standard specifies the names and codes of soils of different classes, subclasses, groups, subgroups, genera and species in the Chinese soil classification system.
This standard is applicable to the identification of soil information in processes such as soil survey, soil statistical information summary, soil information exchange and processing and soil resource utilization.
2 Classification Principles and Method
For the purposes of this standard, the soil classification units are classified into six levels, i.e., class, subclass, group, subgroup, genus and species using linear classification method based on the basic principles of information classification such as scientificity, integrity, systematicness, practicability, extendibility and compatibility.
3 Code Structure and Coding Method
3.1 Code Structure
In this standard, the soils of different levels in the Chinese soil classification system are coded using the hierarchical coding method. The code structure is shown in Figure 1.
Figure 1 Soil Code Structure in Chinese Soil Classification System
3.2 Coding Method
According to the six-level eight-digit code structure in 3.1, the specific coding method of the Chinese soil code is:
a) The class code is expressed by one uppercase English letter in Level 1;
b) The subclass code is expressed by the class code plus one Arabic numeral in Level 2;
c) The group code is expressed by the subclass code plus one Arabic numeral in Level 3;
d) The subgroup code is expressed by the group code plus one Arabic numeral in Level 4;
e) The genus code is expressed by the subgroup code plus two Arabic numerals in Level 5;
f) The species code is expressed by the genus code plus two Arabic numerals in Level 6.
3.3 Miscellaneous
3.3.1 Meaning of the numeral 0 in a code
In the classification unit that is not subdivided, the lower-level code is expressed by its upper-level code plus 0, and the name of the lower-level soil is unchanged.
Example 1: the solonetz subclass is not subdivided and the code of soil in the level is expressed by the solonetz subclass code K2 plus a 0, i.e., K20, and the name of soil group is remained as “solonetz”.
Example 2: the subgroup and genus under gelisols group are not subdivided, and their codes are expressed by the gelisols group code M41 plus 0, i.e., M410 and M41000 respectively; the name of such subgroup or genus is remained as “gelisols”.
The coding order of the two-digit code structure of the soil genus and species starts from 11 (except the soils not subdivided below subclass), and the codes with the second digit of 0 (e.g., 20, 30, 40, etc.) are avoided.
3.3.2 Toponyms prefixed to the soil species and those in the description
In order to avoid that two different soils share the same name, the name of some soil species is prefixed with the toponym of place where its typical section is located. However, this does not mean that this soil species is only distributed in this region. The name of the province (city or autonomous region) is also indicated in the description column of this standard, which only indicates that such soil species is firstly identified in this province (city or autonomous region), and does not mean the limitation of the distribution area; such soil species may also be distributed in other provinces (cities and autonomous regions).
3.3.3 Treatment of soil species not explicitly listed in the code table
In the soil level, any soil species not explicitly listed in this standard may be treated in the following two ways:
a) Incorporated into the code ended with 99 under its genus.
Example: code L1111199 indicates various "other fluvo-aquic mud field" species that are not explicitly listed in the fluvo-aquic mud field genus in this standard.
b) Added with new codes following the soil species code given in this standard.
Example: codes such as L1111145 and L1111146 may be added following the code L1111144, but they are only valid for the internal use of its own system.
Foreword i
Introduction ii
1 Scope
2 Classification Principles and Method
3 Code Structure and Coding Method
3.1 Code Structure
3.2 Coding Method
3.3 Miscellaneous
4 Table for Classification and Codes
Annex A (Informative) Change and Comparison of Names and Codes of Soil
Annex B (Informative) Index Table for Classification and Codes of Chinese Soil
Standard
GB/T 17296-2009 Classification and codes for Chinese soil (English Version)
1 Scope
This standard specifies the names and codes of soils of different classes, subclasses, groups, subgroups, genera and species in the Chinese soil classification system.
This standard is applicable to the identification of soil information in processes such as soil survey, soil statistical information summary, soil information exchange and processing and soil resource utilization.
2 Classification Principles and Method
For the purposes of this standard, the soil classification units are classified into six levels, i.e., class, subclass, group, subgroup, genus and species using linear classification method based on the basic principles of information classification such as scientificity, integrity, systematicness, practicability, extendibility and compatibility.
3 Code Structure and Coding Method
3.1 Code Structure
In this standard, the soils of different levels in the Chinese soil classification system are coded using the hierarchical coding method. The code structure is shown in Figure 1.
Figure 1 Soil Code Structure in Chinese Soil Classification System
3.2 Coding Method
According to the six-level eight-digit code structure in 3.1, the specific coding method of the Chinese soil code is:
a) The class code is expressed by one uppercase English letter in Level 1;
b) The subclass code is expressed by the class code plus one Arabic numeral in Level 2;
c) The group code is expressed by the subclass code plus one Arabic numeral in Level 3;
d) The subgroup code is expressed by the group code plus one Arabic numeral in Level 4;
e) The genus code is expressed by the subgroup code plus two Arabic numerals in Level 5;
f) The species code is expressed by the genus code plus two Arabic numerals in Level 6.
3.3 Miscellaneous
3.3.1 Meaning of the numeral 0 in a code
In the classification unit that is not subdivided, the lower-level code is expressed by its upper-level code plus 0, and the name of the lower-level soil is unchanged.
Example 1: the solonetz subclass is not subdivided and the code of soil in the level is expressed by the solonetz subclass code K2 plus a 0, i.e., K20, and the name of soil group is remained as “solonetz”.
Example 2: the subgroup and genus under gelisols group are not subdivided, and their codes are expressed by the gelisols group code M41 plus 0, i.e., M410 and M41000 respectively; the name of such subgroup or genus is remained as “gelisols”.
The coding order of the two-digit code structure of the soil genus and species starts from 11 (except the soils not subdivided below subclass), and the codes with the second digit of 0 (e.g., 20, 30, 40, etc.) are avoided.
3.3.2 Toponyms prefixed to the soil species and those in the description
In order to avoid that two different soils share the same name, the name of some soil species is prefixed with the toponym of place where its typical section is located. However, this does not mean that this soil species is only distributed in this region. The name of the province (city or autonomous region) is also indicated in the description column of this standard, which only indicates that such soil species is firstly identified in this province (city or autonomous region), and does not mean the limitation of the distribution area; such soil species may also be distributed in other provinces (cities and autonomous regions).
3.3.3 Treatment of soil species not explicitly listed in the code table
In the soil level, any soil species not explicitly listed in this standard may be treated in the following two ways:
a) Incorporated into the code ended with 99 under its genus.
Example: code L1111199 indicates various "other fluvo-aquic mud field" species that are not explicitly listed in the fluvo-aquic mud field genus in this standard.
b) Added with new codes following the soil species code given in this standard.
Example: codes such as L1111145 and L1111146 may be added following the code L1111144, but they are only valid for the internal use of its own system.
Contents of GB/T 17296-2009
Foreword i
Introduction ii
1 Scope
2 Classification Principles and Method
3 Code Structure and Coding Method
3.1 Code Structure
3.2 Coding Method
3.3 Miscellaneous
4 Table for Classification and Codes
Annex A (Informative) Change and Comparison of Names and Codes of Soil
Annex B (Informative) Index Table for Classification and Codes of Chinese Soil
