Subject | SSURGO Soil Map Coverage | U.S. General Soil Map Coverage |
Number of Survey Areas in the Entire Map Coverage | A little over 3000. | One. |
Can tabular data for a survey area exist with no corresponding spatial data? | Yes. | No. |
Can spatial data for a survey area exist with no corresponding tabular data? | No. | No. |
Source Maps | 1:12,000 or 1:24,000 orthophotos. | 1:250,000 topographic quadrangles. |
Minimum Size Map Delineation | One to ten acres. | 2,500 acres. |
Distribution Bundling | Data is bundled by soil survey area, regardless of the number of soil survey areas requested. | Data is either bundled by soil survey area or by a state or territory subset of the entire survey area, regardless of the number of state or territory subsets requested. |
Distribution Datum | North American Datum of 1983. | North American Datum of 1983. |
Distribution Projection or Grid | Geographic coordinates, UTM or State Plane. | Geographic coordinates only. |
Distribution Spatial Format | ESRI Shapefile, ArcInfo Coverage or Interchange. | ESRI Shapefile only. |
Raster or Vector? | Vector (Polygons, Lines and Points). | Vector (Polygons, Lines and Points). |
Available Feature Classes | Survey Area Polygon (required). Map Unit Polygon (required). Line Map Units (optional). Point Map Units (optional). Line Spot Features (optional). Point Spot Features (optional). | Map Unit Polygon (required). |
Distribution Tabular Format | Text files in ASCII, pipe (|) field delimited and double quote text delimited. One file per database table. | Text files in ASCII, pipe (|) field delimited and double quote text delimited. One file per database table. |
Tabular Data Includes “Fuzzy Logic” Soil Interpretations? | Yes. | No. |
Underlying Tabular Data Model | SSURGO*. | SSURGO*. |
Is the dataset available through Web Soil Survey? | Yes. | No. |
Subject | SSURGO Soil Map Coverage | U.S. General Soil Map Coverage |
Number of Survey Areas in the Entire Map Coverage | A little over 3000. | One. |
Is a corresponding survey area status map available? | Yes. | No. |
Survey Area Selection | A user must select a specific survey area before doing anything else. | There is no explicit survey area selection process. |
Version Information on the Download Page | Since tabular data can be updated independent of spatial data, tabular, spatial and survey area version are all displayed. | Since tabular data is never updated independent of spatial data, only survey area version is displayed. The tabular and spatial version will always be the same as the survey area version. |
Can data for the entire map coverage be downloaded at once? | No. Only data for a single survey area may be included in a download request. | Yes. |
Can data for only part of a survey area be downloaded? | No. | Yes. A state or territory subset of data for the entire map coverage can be downloaded. |
Can tabular data be downloaded independent of spatial data, and vice versa? | Yes. | No. |
Can I choose which SSURGO template database is included in a download? | Yes. | No. The national SSURGO template database is always included. |
For a download, can I specify the spatial format and coordinate system? | Yes. | No. Data is always provided in ESRI Shapefile format, and in geographic coordinates. |
Through this website, can I generate soil reports for this data? | Yes. | No. |
Can I subscribe to a survey area? | Yes. | No. |
Subject | SSURGO Soil Map Coverage | U.S. General Soil Map Coverage |
Export Packaging | Spatial extent is indicated in a file or directory name by a 5 character survey area symbol, e.g. “tx039”. | Spatial extent is indicated in a file or directory name by a 2 character country, state or territory symbol, e.g. “us”, “tx”, “pr”, etc. |
Can tabular data be imported into a SSURGO template database?* | Yes. | Yes. |
Can more than one set of tabular data be imported into the same SSURGO template database?* | Yes, as long as data for the corresponding survey area doesn’t already reside in the database, and there is still room in the database. | No. Data for more than one state or territory subset cannot be imported into the same database. |
Can tabular data for every survey area be imported into the same SSURGO template database?* | No. | Yes, but it takes a very long time, and performance after it has been imported may be poor. |
In a SSURGO template database, can soil reports be generated? | Yes. | Yes, but in general you should select a subset of map units before generating a report due to performance considerations. |
Can the data be used with Client Soil Data Viewer? | Yes. | For a state subset? – Yes, but performance may be poor. For the entire U.S.? – No. Since U.S. General Soil Map data doesn’t include fuzzy logic soil interpretations, the SDV rules for fuzzy logic soil interpretations will not be available. |
*“SSURGO” is a term that refers to both a specific soil map coverage and a specific data model for aggregated soil data.
Although the SSURGO Soil Map Coverage is different from the U.S. General Soil Map Coverage, from a tabular data standpoint,
both datasets share the same underlying data model. This is why both datasets can be imported into a “SSURGO template database”.
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