The correspondence between the FAO-Unesco legends of 1974 and 1988

The official correspondence of Appendix 4 of the Revised Legend (FAO 1988, "Main changes in the revised legend", pp. 113-126) between the 26 major soil groups and 106 soil units of the Legend of 1974 and the 28 major soil groupings and 153 soil units of 1988, with the three changes the appendix does not flag added in brackets (Calcaric Gleysols to Calcic Gleysols is a change of definition; the Plinthic Luvisols have no 1988 row; the Thionic Histosols are new). For display and for reading labelled data only: it never classifies (classify_fao keys each edition by its own text).

Usage

fao_crosswalk(code = NULL, from = c("1974", "1988"))

Arguments

code

Optional character vector of codes to look up, of the edition from (a group, grouping or unit: "Lo", "L"; "LXh", "LX"). NULL (default) for the whole table.

from

"1974" (default): one row per 1974 class; the 1988 codes it goes to. "1988": the rows whose 1988 side names the code (as a target or as one of soilKey's alternatives), and the rows of the 1988 classes with no 1974 class (relation "new").

Value

A data.frame with level ("group" or "unit"), code_1974, name_1974, code_1988 and name_1988 (several joined by ", "; empty when deleted), relation ("same", "renamed", "amended", "renamed_amended", "merged", "split", "deleted", "new"), also and also_when (soilKey's alternative 1988 targets read from a group comment of the appendix, such as the Lixisols for a low activity Luvisol, and when they apply), page (printed page of 1988), bracketed (TRUE for a row the appendix does not print) and note (the comment, paraphrased).

References

FAO (1988). FAO/Unesco Soil Map of the World, Revised Legend. World Soil Resources Report 60, FAO, Rome; ISRIC reprint 1997, Appendix 4.

See also

classify_fao.

Examples

fao_crosswalk(c("Lo", "Gc", "Vp", "Y"))[, c("code_1974", "code_1988", "relation", "also")]
#>   code_1974          code_1988        relation                       also
#> 1         Y                            deleted CL, GY, CM, LV, LX, RG, AR
#> 2        Gc                GLk renamed_amended                           
#> 3        Vp VRe, VRd, VRk, VRy           split                           
#> 4        Lo                LVh renamed_amended                        LXh
fao_crosswalk("LXh", from = "1988")[, c("code_1974", "code_1988", "relation")]
#>   code_1974 code_1988        relation
#> 1        Lo       LVh renamed_amended
#> 2        Lc       LVx            same
#> 3        Lk       LVk            same
#> 4        Lv       LVv            same
#> 5      <NA>       LXh             new