This data set consists of general soil association units. It was develped by the National Cooperative Soil Survey and supersedes
the State Soil Geographic (STATSGO) data set published in 1994. It consists of a broad based inventory of soils and nonsoil
areas that occur in a repeatable pattern on the landscape and that can be cartographically shown at the scale mapped. The
data set was created by generalizing more detailed soil survey maps. Where more detailed soil survey maps were not available,
data on geology, topography, vegetation, and climate were assembled, together with Land Remote Sensing Satellite (LANDSAT)
images. Soils of like areas were studied, and the probable classification and extent of the soils were determined. Map unit
composition was determined by transecting or sampling areas on the more detailed maps and expanding the data statistically
to characterize the whole map unit. This data set consists of georeferenced vector digital data and tabular digital data.
The map data were collected in 1-by 2-degree topographic quadrangle units and merged into a seamless national data set. It
is distributed in state/territory and national extents. The soil map units are linked to attributes in the National Soil Information
System data base which gives the proportionate extent of the component soils and their properties.
Citation
Title Digital General Soil Map of U.S.
publication Date
2006-07-05
presentationForm
TABULAR DIGITAL DATA AND VECTOR DIGITAL DATA
cited responsible party
-
publisher
organisation Name
U.S. Department of Agriculture, Natural Resources Conservation Service
Contact information
Address
, Fort Worth, Texas
cited responsible party
-
originator
organisation Name
U.S. Department of Agriculture, Natural Resources Conservation Service
Title U.S. Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative
Divisions (Federal Information Processing Standard 10-4): Washington, DC, National Institute of Standards and Technology.
Location keywords:
USA
thesaurus name >
Title None
purpose:
These data provide information about soil features on or near the surface of the Earth. Data were collected as part of the
National Cooperative Soil Survey. These data are intended for geographic display and analysis at the state, regional, and
national level. The data should be displayed and analyzed at scales appropriate for 1:250,000-scale data.
Resource language:
eng; USA
Resource progress code:
completed
Resource Maintenance Information
maintenance or update frequency:
asNeeded
Constraints on resource usage:
Constraints
Use limitation statement:
Although data in this product have been processed successfully on a computer system at the U.S. Department of Agriculture,
no warranty expressed or implied is made by the Agency regarding the utility of the data on any other system, nor shall the
act of distribution constitute any such warranty. The U.S. Department of Agriculture will warrant the delivery of this product
in computer-readable format, and will offer appropriate adjustment of credit when the product is determined unreadable by
correctly adjusted computer input peripherals, or when the physical medium is delivered in damaged condition. Request for
adjustment of credit must be made within 90 days from the date of this shipment from the ordering site. The U.S. Department
of Agriculture, nor any of its agencies are liable for misuse of the data. It is also not liable for damage, transmission
of viruses, or computer contamination through the distribution of these data sets. The U.S. Department of Agriculture prohibits
discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs,
and marital or familial status. (Not all prohibited bases apply to all programs.)
Constraints on resource usage:
Legal Constraints
use constraint:
otherRestrictions
Other constraints
Use Constraints: The U.S. Department of Agriculture, Natural Resources Conservation Service should be acknowledged as the
data source in products derived from these data. Hardcopies utilizing these data shall clearly indicate their source. User
agrees not to misrepresent these data, nor to imply that changes made were approved by the Natural Resources Conservation
Service. The Digital General Soil Map of U.S. was designed primarily for regional, multicounty, river basin, State, and multistate
resource planning, management, and monitoring. Data are not detailed enough to make interpretations at a county level. This
soil survey product is not designed for use as a primary regulatory tool in permitting or citing decisions, but may be used
as a reference source. The use of these data is not restricted and may be interpreted by organizations, agencies, units of
government, or others; however, they are responsible for its appropriate application. Federal, State, or local regulatory
bodies are not to reassign to the Natural Resources Conservation Service any authority for the decisions that they make. The
Natural Resources Conservation Service will not perform any evaluations of these maps for purposes related solely to state
or local regulatory programs. When data from the Digital General Soil Map of U.S. are overlayed with other data layers, such
as land use data, caution must be used in generating statistics on the co-occurence of the land use data with the soil data.
The composition of the soil map unit can be characterized independently for the land use and for the soil component, but there
are no data on their joint occurrence at a more detailed level. Analysis of the overlayed data should be on a map polygon
basis. Additional political, watershed, or other boundaries may be intersected with the soil data. Although the composition
of each political and watershed unit may be described in terms of the soil map units, information is not available to assign
the components to the boundary units with full accuracy. As with the land use categories, the analysis should be restricted
to the classified components. The approximate minimum area delineated is 625 hectares (1,544 acres), which is represented
on a 1:250,000-scale map by an area approximately 1 cm by 1 cm (0.4 inch by 0.4 inch). Linear delineations are not less than
0.5 cm (0.2 inch) in width. The number of delineations per 1:250,000 quadrangle typically is 100 to 200, but may range up
to 400. Delineations depict the dominant soils making up the landscape. Other dissimilar soils, too small to be delineated,
are present within a delineation. Digital enlargements of these data to scales greater than at which they were originally
mapped can cause misinterpretation of the data. If enlarged, maps do not show the small areas of contrasting soils that could
have been shown at a larger scale. The depicted soil boundaries, interpretations, and analysis derived from them do not eliminate
the need for onsite sampling, testing, and detailed study of specific sites for intensive uses. Thus, these data and their
interpretations are intended for planning purposes only. Data values for some data elements may be incomplete or missing.
Where data are unavailable, a mask should be used to exclude the area from analysis. The spatial and tabular data used to
create this product are periodically updated. Data are versioned, and users are responsible for obtaining the latest version
of the product.
Constraints on resource usage:
Legal Constraints
Access Constraints
otherRestrictions
Other constraints
Access Constraints: None
Spatial representation type code:
vector
Resource extent
Geographic Extent
Geographic Bounding Box
westBoundLongitude
-110.0
eastBoundLongitude
-102.0
northBoundLatitude
41.0
southBoundLatitude
37.0
Temporal Extent
2000-01-01
2006-07-05
point of contact
-
pointOfContact
organisation Name
U.S. Department of Agriculture, Natural Resources Conservation Service
position Name State Soil Scientist
Contact information
Telephone
Voice 907-761-7759
Address
USDA - Natural Resources Conservation ServiceAlaska State Office800 West Evergreen, Suite 100, Palmer, AK, 99645-6546
source description
Source Contribution: base information for development of map unit delineations and transect data for naming map units Source
Type paper
source citation
Title multiple soil survey publications
publication Date
presentationForm
mapDigital
cited responsible party
-
publisher
organisation Name
U.S. Government Printing Office
Contact information
Address
, Washington, D.C.
cited responsible party
-
originator
organisation Name
U.S Department of Agriculture, Natural Resources Conservation Service
Resource extent
Temporal Extent
source
source description
Source Contribution: reference information for development of map unit delineations and transect data for naming map units
where detailed surveys did not exist Source Type paper
source citation
Title multiple reconnaissance, county, and State general soil maps
publication Date
presentationForm
mapDigital
cited responsible party
-
publisher
organisation Name
U.S. Government Printing Office
Contact information
Address
, Washington, D.C.
cited responsible party
-
originator
organisation Name
U.S Department of Agriculture, Natural Resources Conservation Service
Resource extent
Temporal Extent
source
source description
Source Contribution: base materials for compilation of map unit delineation linework Source Type stable-base material
representative resolution scale:
Scale denominator: 250000
source citation
Title multiple maps
publication Date
presentationForm
mapDigital
cited responsible party
-
publisher
organisation Name
U.S. Geological Survey
Contact information
Address
, Reston, Virginia
cited responsible party
-
originator
organisation Name
U.S. Geological Survey
Resource extent
Temporal Extent
source
source description
Source Contribution: digitizing sourceSource Type stable-base material
source citation
Title multiple compiled mylar overlays of map unit delineations, unpublished
publication Date
presentationForm
ANNOTATED OVERLAY
cited responsible party
-
originator
organisation Name
U.S Department of Agriculture, Natural Resources Conservation Service
Resource extent
Temporal Extent
source
source description
Source Contribution: source material of soil map unit delineations and soil symbols Source Type CD-ROM
representative resolution scale:
Scale denominator: 250000
source citation
Title State Soil Geographic (STATSGO) data base
publication Date
1994-01-01
presentationForm
DIGITAL DATA
cited responsible party
-
originator
organisation Name
U.S. Department of Agriculture, Natural Resources Conservation Service
Resource extent
Temporal Extent
1994-01-01
source
source description
Source Contribution: attribute (tabular) informationSource Type database
source citation
Title National Soil Information System (NASIS) data base
publication Date
2005-01-01
presentationForm
tableDigital
cited responsible party
-
publisher
organisation Name
U.S. Department of Agriculture, Natural Resources Conservation Service
Contact information
Address
, Fort Collins, Colorado
cited responsible party
-
originator
organisation Name
U.S. Department of Agriculture, Natural Resources Conservation Service
Resource extent
Temporal Extent
2005-01-01
2005-01-01
AbsoluteExternalPositionalAccuracy
name Of Measure Horizontal Positional Accuracy Report
evaluation Method Description
The accuracy of these digital data is based upon their compilation to base maps that meet National Map Accuracy Standards.
The difference in positional accuracy between the map unit boundaries in the field and their digitized map locations is unknown.
The locational acuracy of soil delineations on the ground varies with the transition between map units. For example, in areas
where changes in soils, climate, topography, and geology occur subtly across a portion of a state, the transition between
soil map unit boundaries will be gradual. Where these features change abruptly, such as from an area of foothills to a lake
plain, the transition will be very narrow. Soil delineation boundaries were digitized within 0.01 inches of their locations
on the digitizing source. The digital map elements are edge matched between data sets. The data along each state boundary
are matched against the data for the adjacent state. Edge locations generally do not deviate from centerline to centerline
by more than 0.01 inch.
Completeness Commission
evaluation Method Description
A map unit is a collection of areas defined and named the same in terms of their soil and/or nonsoil areas. Each map unit
differs in some respect from all others in a survey area and is uniquely identified. Each individual area is a delineation.
Each map unit in the Digital General Soil Map of U.S. consists of one to more than 21 components. In those few areas where
detailed maps did not exist, reconnaissance soil surveys were combined with data on geology, topography, vegetation, climate,
and remote sensing images to delineate map units and estimate the percentages of components. Map unit components in this product
are soil series phases, and their percent composition represents the estimated areal proportion of each within a map unit.
The composition for a map unit is generalized to represent the statewide extent of that map unit and not the extent of any
single map unit delineation. These specifications provide a nationally consistent representation of the associated attribute
data. The actual composition and interpretive purity of the map unit delineations were based on statistical analysis of transect
data. The composition was largely determined by measuring transects on detailed soil survey maps. The number of transects
used was proportional to the relative size, number, and complexity of the delineations. The combined data on the length of
the map units crossed by the transects were used to determine the percentages of the different soil and nonsoil areas in each
map unit. Specific National Cooperative Soil Survey Standards and procedures were used in the classification of soils, design
and name of map units. These standards are outlined in U.S. Department of Agriculture. 2nd Ed., 1999. Soil Taxonomy: A basic
system of soil classification for making and interpreting soil surveys. Nat. Res. Conserv. Serv., U.S. Dep. Agric. Handb.
436.; U.S. Department of Agriculture. 9th Ed., 2003. Keys to Soil Taxonomy. Soil Surv. staff, Nat. Res. Conserv. Serv.; U.S.
Department of Agriculture. Current Issue. National Soil Survey Handbook, title 430-VI. Soil Surv. Staff, Nat. Res. Conserv.
Serv.; and U.S. Department of Agriculture. 1993. Soil Survey Manual. Soil Surv. Staff, U.S. Dep. Agric. Handbook 18. Adherence
to National Cooperative Soil Survey standards and procedures is based on peer review, quality control, and quality assurance.
Quality control is outlined in documents that reside with the Natural Resources Conservation Service state soil scientist.
Completeness Omission
evaluation Method Description
A map unit is a collection of areas defined and named the same in terms of their soil and/or nonsoil areas. Each map unit
differs in some respect from all others in a survey area and is uniquely identified. Each individual area is a delineation.
Each map unit in the Digital General Soil Map of U.S. consists of one to more than 21 components. In those few areas where
detailed maps did not exist, reconnaissance soil surveys were combined with data on geology, topography, vegetation, climate,
and remote sensing images to delineate map units and estimate the percentages of components. Map unit components in this product
are soil series phases, and their percent composition represents the estimated areal proportion of each within a map unit.
The composition for a map unit is generalized to represent the statewide extent of that map unit and not the extent of any
single map unit delineation. These specifications provide a nationally consistent representation of the associated attribute
data. The actual composition and interpretive purity of the map unit delineations were based on statistical analysis of transect
data. The composition was largely determined by measuring transects on detailed soil survey maps. The number of transects
used was proportional to the relative size, number, and complexity of the delineations. The combined data on the length of
the map units crossed by the transects were used to determine the percentages of the different soil and nonsoil areas in each
map unit. Specific National Cooperative Soil Survey Standards and procedures were used in the classification of soils, design
and name of map units. These standards are outlined in U.S. Department of Agriculture. 2nd Ed., 1999. Soil Taxonomy: A basic
system of soil classification for making and interpreting soil surveys. Nat. Res. Conserv. Serv., U.S. Dep. Agric. Handb.
436.; U.S. Department of Agriculture. 9th Ed., 2003. Keys to Soil Taxonomy. Soil Surv. staff, Nat. Res. Conserv. Serv.; U.S.
Department of Agriculture. Current Issue. National Soil Survey Handbook, title 430-VI. Soil Surv. Staff, Nat. Res. Conserv.
Serv.; and U.S. Department of Agriculture. 1993. Soil Survey Manual. Soil Surv. Staff, U.S. Dep. Agric. Handbook 18. Adherence
to National Cooperative Soil Survey standards and procedures is based on peer review, quality control, and quality assurance.
Quality control is outlined in documents that reside with the Natural Resources Conservation Service state soil scientist.
ConceptualConsistency
measure Description
Certain node/geometry and topology (GT)-polygon/chain relationships are collected or generated to satisfy topological requirements.
(The GT-polygon corresponds to the soil delineation). Some of these requirements include: chains must begin and end at nodes,
chains must connect to each other at nodes, chains do not extend through nodes, left and right GT-polygons are defined for
each chain element and are consistent throughout, and the chains representing the limits of the file (neatline) are free of
gaps. The tests of logical consistency are performed using vendor software. The neatline is generated by connecting the explicitly
entered four corners of the digital file. All data outside the enclosed region are ignored and all data crossing these geographically
straight lines are clipped at the neatline. Data within a specified tolerance of the neatline are snapped to the neatline.
Neatline straightening aligns the digitized edges of the digital data with the generated neatline (i.e., with the longitude/latitude
lines in geographic coordinates). All internal polygons are tested for closure with vendor software and are checked on hard
copy plots. All data are checked for common soil lines (i.e., adjacent polygons with the same label). Quadrangles are edge
matched within the state, merged into a statewide data sets, and then edge matched to adjacent state data sets. Edge locations
do not deviate from centerline to centerline by more than 0.01 inch.
organisation Name
U.S. Department of Agriculture, Natural Resources Conservation Service, National Cartography and Geospatial Center
Contact information
Telephone
Voice (800) 672-5559
Fax (817) 509-3469
Address
501 West Felix Street, Building 23P.O. Box 6567, Fort Worth, Texas, 76115
Standard ordering process
fees There is currently no direct charge for requesting data or for retrieval via FTP.
Ordering Instructions
Access Instructions: Select desired survey area at above Internet Web site. An email address is required for receipt of instructions
on retrieval via anonymous FTP. Anticipate a delay between submission of request at Web site and receipt of email message.
Select desired survey area at above Internet Web site. An email address is required for receipt of instructions on retrieval
via anonymous FTP. Anticipate a delay between submission of request at Web site and receipt of email message. Select desired
survey area at above Internet Web site. An email address is required for receipt of instructions on retrieval via anonymous
FTP. Anticipate a delay between submission of request at Web site and receipt of email message. Select desired survey area
at above Internet Web site. An email address is required for receipt of instructions on retrieval via anonymous FTP. Anticipate
a delay between submission of request at Web site and receipt of email message. Ordering Instructions: Visit the above mentioned
Internet Web Site, select state or territory, then select individual soil survey area of interest. Spatial line data and locations
of special feature symbols are in ESRI ArcGIS (ArcView,ArcInfo) shapefile, coverage and interchange (i.e., export) formats.
The National Soil Information System attribute soil data are available in variable length, pipe delimited, ASCII file format.
notes: This metadata was automatically generated from the Content Standards for Digital Geospatial Metadata standard (version FGDC-STD-001-1998)
using the 2012-06-20T17:21:00 version of the FGDC RSE to ISO 19115-2 transform.
Metadata Constraints
Legal Constraints
Access Constraints
otherRestrictions
Other constraints
Metadata Use Constraints: none
Metadata contact
-
pointOfContact
organisation Name
U.S. Department of Agriculture, Natural Resources Conservation Service
position Name State Soil Scientist
Contact information
Telephone
Voice 907-761-7759
Address
USDA - Natural Resources Conservation ServiceAlaska State Office800 West Evergreen, Suite 100, Palmer, AK, 99645-6546