Natural Resources Conservation Service (NRCS) GIS Data

Overview | National Resources Inventory | STATSGO Soils | SSURGO Soils| Other Resources | Documentation and Links

Overview

A wide range of GIS data resources are available from the USDA Natural Resources Conservation Service. Highlights include the US General Soils Map (STATSGO2), SSURGO soils, and the National Resources Inventory (NRI) all of which are documented on this page.

Online Mapping, downloading, and data ordering of many NRCS GIS data layers are available from the Geospatial Data Gateway.

US General Soils (STATSGO2)


STATSGO polygons for NC
NC STATSGO data (very generalized)

The US General Soil Map (STATSGO2) consists of "state general soil maps made by generalizing the detailed soil survey data. The level of mapping is designed to be used for broad planning and management uses covering state, regional, and multi-state area. The original STATSGO (stands for State Soil Geographic Database) data were revised and updated in 2006, and hence renamed. Contact Data Services if you need a copy of the original STATSGO data for North Carolina.

STATSGO2 data, may be downloaded by state from the Soil Data Mart. There are more details here. Metadata and a SSURGO comparison are also available from the above data access site.

A copy of North Carolina's STATSOG2 data is archived on the Geodata Server under /fedgov/nrcs/statsgo2.


SSURGO Soils

SSURGO polygons for NC
Northern Wake Co. SSURGO data.

The Soil Survey Geographic (SSURGO) Data Base consists of 1:12,000 to 1:63,360 scale detailed local soils data. "SSURGO digitizing duplicates the original soil survey maps. This level of mapping is designed for use by landowners, townships, and county natural resource planning and management. The user should be knowledgeable of soils data and their characteristics."--(NRCS site).

SSURGO data is downloadable in various formats and projections for most of the US (status graphic) from:

  • Soil Data Mart - Focus is on downloading data by County. Selecting small areas, or multi-county areas is not possible.
  • Web Soil Survey - Focus is on viewing maps and data online for small areas of interest. First, you must create an "Area of Interest" to work with.

It is recommended that you use SSURGO data only from one of these two sites because they have been certified by NRCS for accuracy. Note that you will not be able to download the data immediately from the Soil Data Mart, but will instead have your request put into a queue, which may take several minutes or possibly days to get to your request. Metadata are also available for each dataset and extensive documentation is available.

Additional Notes

  • If you are using ArcGIS, working with SSURGO data is MUCH easier by using the NRCS Soil Data Viewer. This is an ArcMap extension that handles downloading the data and automatically makes soil mapping unit attribute joins to the appropriate databases. Analyses and report generation has been made very simple with this extension.

    Otherwise, since SSURGO data only comes with a soil mapping unit attribute, you'll need to manually join additional soil survey attributes downloaded in tabular format from the Soil Data Mart. Contact Data Services for questions about the process.

  • Older soils data that were digitized by NC CGIA (status graphic) are available in ArcInfo Coverage format and shapefiles on the Geodata server (see the Detailed Data Listing and additional CGIA data).

  • All the SSURGO spatial and tabular data for NC available during the summer of 2005 was downloaded (thanks to Tom Colson at the NCSU CEO) and is on the Geodata server under fedgov/nrcs/ncsoils. This is useful if your download request from the Soil Data Mart will take several hours or days. Files are named according to their FIPS Number.

Other NRCS Data Resources

The National Resources Inventory "...is a statistically based sample of land use and natural resource conditions and trends on U.S. nonfederal lands. It is the most comprehensive database of its kind ever attempted anywhere in the world" (NRCS). Since 1982, the NRI was conducted every 5 years; but, beginning with 2001, it is conducted annually.

Two CD-ROM products have been released of the NRI and are available from DH Hill Library:

According to the NRI website, annual inventory data is only available via the website (limited summary) or the NRI Online Analysis System used by NRI Coordinators.


Documentation and Links

NRCS Web site

NRCS Data, Maps, & Analysis


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