eng
utf8
dataset
dataset
Soils Hotline
U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Survey Center
402-437-5379
100 Centennial Mall North, Room 152
Lincoln
NE
68508-3866
US
soilshotline@usda.gov
pointOfContact
2022-12-07
NAP - Metadata
1.2
Soil Survey Geographic Database (SSURGO)
SSURGO
2021-10-01
revision
mapDigital
tableDigital
Soil Survey Geographic Database
This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The information was prepared by digitizing maps, by compiling information onto a planimetric correct base and digitizing, or by revising digitized maps using remotely sensed and other information. This data set consists of georeferenced digital map data and computerized attribute data. The map data are in a soil survey area extent format and include a detailed, field verified inventory of soils and miscellaneous areas that normally occur in a repeatable pattern on the landscape and that can be cartographically shown at the scale mapped. A special soil features layer (point and line features) is optional. This layer displays the location of features too small to delineate at the mapping scale, but they are large enough and contrasting enough to significantly influence use and management. The soil map units are linked to attributes in the National Soil Information System relational database, which gives the proportionate extent of the component soils and their properties.
SSURGO depicts information about the kinds and distribution of soils on the landscape. The soil map and data used in the SSURGO product were prepared by soil scientists as part of the National Cooperative Soil Survey.
Soil Survey Staff. 2021. Soil Survey Geographic (SSURGO) Database. United States Department of Agriculture, Natural Resources Conservation Service. Available online at https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053627 (accessed 1 June 2021).
Soils Hotline
U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Survey Center
402-437-5379
100 Centennial Mall North, Room 152
Lincoln
NE
68508-3866
US
soilshotline@usda.gov
pointOfContact
annually
CONUS
USA
United States of America
Alaska
Hawaii
Puerto Rico
American Samoa
Federated States of Micronesia
Guam
Republic of the Marshall Islands
Commonwealth of the Northern Mariana Islands
Republic of Palau
U.S. Virgin Islands
place
NCSS
NGDA
NRCS
soil map
soil survey
soils,
SSURGO
USDA
theme
Other Documents
The U.S. Department of Agriculture, Natural Resources Conservation Service, should be acknowledged as the data source in products derived from these data.This dataset is not designed for use as a primary regulatory tool in permitting or siting decisions, but may be used as a reference source. This is public information and may be interpreted by organizations, agencies, units of government, or others based on needs; however, they are responsible for the 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. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data.
The U.S. Department of Agriculture (USDA) prohibits discrimination against its customers, employees, and applicants for employment on the bases of race, color, national origin, age, disability, sex, gender identity, religion, reprisal, and where applicable, political beliefs, marital status, familial or parental status, sexual orientation, or all or part of an individual's income is derived from any public assistance program, or protected genetic information in employment or in any program or activity conducted or funded by the Department. (Not all prohibited bases will apply to all programs and/or employment activities.) To file a complaint of discrimination, complete, sign and mail the USDA Program Discrimination Complaint Form (PDF), found online at http://www.ascr.usda.gov/complaint_filing_cust.html, or at any USDA office, or call (866) 632-9992 to request the form. Send your completed complaint form or letter to us by mail at: USDA Office of the Assistant Secretary for Civil Rights 1400 Independence Avenue, S.W. Washington, D.C. 20250-9410 Or by email at program.intake@usda.gov. Individuals who are deaf, hard of hearing or have speech disabilities and you wish to file either an EEO or program complaint please contact USDA through the Federal Relay Service at (800) 877-8339 or (800) 845-6136 (in Spanish). Persons with disabilities who wish to file a program complaint, please see information above on how to contact us by mail directly or by email. If you require alternative means of communication for program information (e.g., Braille, large print, audiotape, etc.) please contact USDA's TARGET Center at (202) 720-2600 (voice and TDD).
vector
eng
utf8
farming
environment
geoscientificInformation
Microsoft Windows 10 Version 10.0 (Build 19044) ; Esri ArcGIS 12.8.3.29751
true
-179.159
179.8597
-14.37386
71.44106
https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm
Web Soil Survey (WSS)
Web Soil Survey (WSS) provides soil data and information produced by the National Cooperative Soil Survey. It is operated by the USDA Natural Resources Conservation Service (NRCS) and provides access to the largest natural resource information system in the world. NRCS has soil maps and data available online for more than 95 percent of the nation’s counties and anticipates having 100 percent in the near future. The site is updated and maintained online as the single authoritative source of soil survey information..
information
https://sdmdataaccess.nrcs.usda.gov/
Soil Data Access (SDA)
Soil Data Access is the name of a suite of web services and applications whose purpose is to meet requirements for requesting and delivering soil survey spatial and tabular data, that are not being met by the current Web Soil Survey and Geospatial Data Gateway websites..
information
https://nrcs.app.box.com/v/soils/folder/20890497120
Box
Direct download via Box to CONUS and State file geodatabases and GeoTiffs.
information
https://www.nrcs.usda.gov/resources/data-and-reports/soil-survey-geographic-database-ssurgo
Landing page
information
dataset
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 consists of one or more components.
Soil scientists identify small areas of soils or nonsoil areas (special soil features) that have properties and behavior significantly different than the named soils in the surrounding map unit. Other inclusions that have a minimal effect on use and management, or those that could not be precisely located, were not mapped.
Specific limits were established on the classification of soils, design and name of map units, location of special soil features, and the percentages of allowable inclusions. These limits are outlined in Agricultural Handbook 18, Soil Survey Manual, 1993, USDA, SCS; Agricultural Handbook 436, Soil Taxonomy, Soil Survey Staff, 1975, USDA, SCS; and all Amendments; Keys to Soil Taxonomy, Soil Survey Staff, (current issue); National Soil Survey Handbook, title 430-VI, 1996.
The actual composition and interpretive purity of the map unit delineations were based on statistical analysis of field observations and transect data. Adherence to National Cooperative Soil Survey standards and procedures is based on peer review, quality control, and quality assurance. Quality control is outlined in the memorandum of understanding for the soil survey area and in documents that reside with the Natural Resources Conservation Service state soil scientist. Four kinds of map units are used in soil surveys: consociations, complexes, associations, and undifferentiated groups.
Consociations - Consociations are named for the dominant soil. In a consociation, delineated areas are dominated by a single soil taxon and similar soils. At least one half of the pedons in each delineation are of the same soil component so similar to the named soil that major interpretations are not affected significantly. The total amount of dissimilar inclusions of other components in a map unit generally does not exceed about 15 percent if limiting and 25 percent if nonlimiting. A single component of a dissimilar limiting inclusion generally does not exceed 10 percent if very contrasting.
Complexes and associations - Complexes and associations are named for two or more dissimilar components with the dominant component listed first. They occur in a regularly repeating pattern. The major components of a complex cannot be mapped separately at a scale of about 1:24,000. The major components of an association can be separated at a scale Federal Geographic Data Committee FGDC-STD-006 Soil Geographic Data Standard, September 1997 273 of about 1:24,000. In each delineation of either a complex or an association, each major component is normally present, though their proportions may vary appreciably from one delineation to another. The total amount of inclusions in a map unit that are dissimilar to any of the major components does not exceed 15 percent if limiting and 25 percent if nonlimiting. A single kind of dissimilar limiting inclusion usually does not exceed 10 percent.
Undifferentiated groups - Undifferentiated groups consist of two or more components that do not always occur together in the same delineation, but are included in the same named map unit because use and management are the same or similar for common uses. Every delineation has at least one of the major components and some may have all of them. The same principles regarding proportion of inclusions apply to undifferentiated groups as to consociations.
Minimum documentation consists of three complete soil profile descriptions that are collected for each soil added to the legend, one additional per 3,000 acres mapped; three 10 observation
transects for each map unit, one additional 10 point transect per 3,000 acres.
map unit composition
1997-09-01
creation
A defined standard or level of confidence in the interpretive purity of the map unit delineations is attained by adjusting the kind and intensity of field investigations. Field investigations and data collection are carried out in sufficient detail to name map units and to identify accurately and consistently areas of about 2-600 acres.
true
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 soil boundaries and special soil features locations in the field and their digitized map locations is unknown. The locational accuracy of soil delineations on the ground varies with the transition between map units.
For example, on long gently sloping landscapes the transition occurs gradually over many feet. Where landscapes change abruptly from steep to level, the transition will be very narrow.
Soil delineation boundaries and special soil features generally were digitized within 0.01 inch of their locations on the digitizing source.
The digital map elements are edge matched between data sets. The data along each quadrangle edge are matched against the data for the adjacent quadrangle.
Horizontal Positional Accuracy
1997-09-01
creation
Edge locations generally do not deviate from centerline to centerline by more than 0.01 inch.
true
Logical Consistency
1997-09-01
creation
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 Federal Geographic Data Committee FGDC-STD-006 Soil Geographic Data Standard, September 1997 272 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 soil survey area and edge locations generally do not deviate from centerline to centerline by more than 0.01 inch.
true
Attribute accuracy is tested by manual comparison of the source with hard copy plots and/or symbolized display of the map data on an interactive computer graphic system. Selected attributes that cannot be visually verified on plots or on screen are interactively queried and verified on screen. In addition, the attributes are tested against a master set of valid attributes.
Attribute Accuracy
1997-09-01
creation
All attribute data conform to the attribute codes in the signed classification and correlation document and amendment(s) and are current as of the date of digitizing.
true
SSURGO is a compilation of 3,373 individual soil surveys from all 50 states and 10 current and former US Territories. The individual soil surveys where original conducted separately between 1943 to present, but many have since been harmonized to remove bias present between their boundaries.
Data for portions of SSURGO are updated annually as the result of additions of new initial soil surveys or updates to existing ones. The details of each addition or update are documented as projects in the National Soil Information System (NASIS). Projects are carried out by local Soil Survey Offices, and reviewed by Soil Data Quality Specialist, State Soil Scientists, and a Technical Team. Updates are made available after October 1st.
annually