Tag Archives: SSURGO

Convert SSURGO soil data to a Raster Attribute Table

SSURGO (Soil Survey Geographic database) provides soil information across the United States. The data is provide as Shapefiles with the mapping units. The attributes for each polygon are stored as a text files, which need to be imported into an Access database and linked with the shapefile.

An alternative for working with SSURGO data is to convert the shapefile to a raster, parse the text files and store the attributes for each mapping unit as a Raster Attribute Table (RAT).

To do this the following steps are required:

  1. Use gdal_rasterize to create a raster.
  2. Use RSGISLib to convert to a RAT.
  3. Add a column for each attribute using RIOS.

A Python script to perform these steps can be downloaded from https://github.com/MiXIL/SSURGO-Utilities.

An example of usage is:

python convertSSURGO2RAT.py --indir CA669 \
  --colname claytotal_ \
  --outformat KEA

A list of all available columns can be viewed using:

python convertSSURGO2RAT.py --printcols

To export the columns as a standard raster (using RSGISLib) pass in the ‘–raster’ flag.

SSURGO data can be downloaded from the USDA NRCS Geospatial Data Portal (http://datagateway.nrcs.usda.gov/)

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