[GRASS-user] Managing the Harmonized World Soil Database in GRASS

[Luigi Ponti]

Dear listers,

I seem to have successfully imported the Harmonized World Soil Database 
(HWSD) in BIL format to GRASS 6.4.svn via r.in.gdal. The data is 
available at
http://www.iiasa.ac.at/Research/LUC/luc07/External-World-soil-database/HTML/index.html

The HWSD is composed of a raster image file and a linked attribute 
database stored in Microsoft Access 2003 format. According to the 
documentation (page 28)
http://www.iiasa.ac.at/Research/LUC/External-World-soil-database/HWSD_Documentation.pdf

using the HWSD database in a GIS should be straightforward. The 
MU_GLOBAL attribute column in the database is also stored in each raster 
cell, and may therefore be considered as the link to the raster.

My goal would be to obtain more raster maps that show other (soil) 
attributes from the database or combination of different attributes 
based on computations. The documentation suggests the following work flow:

- if necessary, realize the appropriate calculations (ex: after 
exporting from Access to Excel);
- convert final attributes table to a compatible GIS format;
- join the MU_GLOBAL attribute and the GRID value (dbf or txt formats);
- convert the attribute to a new GRID (in the case it is needed).

What comes to mind is value replacement using r.recode but maybe there 
is a better course of action.

This is seemingly the best available soil GIS database with global 
coverage, so I thought my question may be useful to others.

Kind regards and thanks in advance for any hint,

Luigi