There are 13 associated text files of soils characteristics which are keep offline on magnetic media. No interpretations of these characteristics have been made by CGIA: comp; compyld; forest; interp; layer; mapunit; plantnm; taxclass, windbrk; wlhabit; woodland; woodmgt; yldunits <http://www.cgia.state.nc.us/corpmeta.dir/gslnctab.txt> 13 associated tables combined into 1 ascii text file, 2.1 mb system filename: gslnc250 approx. file size = 3.3 mb filename: gslnc250tab.txt. File added in 1993. Revisions and updates to this layer include: 2.) filename: gslnc2501298 The December 1998 update to this layer consisted of projecting the data from NAD27 datum, State Plane projection, units of measure feet TO: NAD83 DATUM, State Plane PROJECTION, UNITS OF MEASURE METERS. This was done to comply with the NC Geographic Information Coordinating Council's "Statement of Direction for North Carolina Corporate Geographic Database Horizontal Reference, Datum and Unit of Measure". This reprojecting was done in various ways depending on the data type and content. Vector data was projected using the 'project' command in ESRI's Arc software and topology was cleaned and built based on coverage needs. Raster data was projected using ESRI's Grid module and various steps as applicable. 1.) filename: nc250gsl88 This 1988 file is the original data and has not been edited. (previously called nc250.gsl)
U.S. Department of Agriculture, Soil Conservation Service, 19981201, onemap_prod.SDEADMIN.gslnc_poly: U.S. Department of Agriculture, Natural Resource Conservation Service, Raleigh, North Carolina.Online Links:
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.001719
Ordinates (y-coordinates) are specified to the nearest 0.001719
Planar coordinates are specified in meters
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.
| Range of values | |
|---|---|
| Minimum: | 341.125 |
| Maximum: | 5277145.500 |
| Units: | meters |
| Resolution: | 0.001 |
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 2,811 |
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 2,812 |
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 1,429 |
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 1,429 |
| Range of values | |
|---|---|
| Minimum: | 33.136 |
| Maximum: | 128,461.477 |
| Units: | meters |
| Resolution: | 0.001 |
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 3,997 |
| Range of values | |
|---|---|
| Minimum: | 1 |
| Maximum: | 4,816 |
GSLNC250.PAT Polygon Attribute Table COLUMN ITEM NAME WIDTH OUTPUT TYPE DEC DESCRIPTION 1 AREA 4 12 F 3 Total area in meters 5 PERIMETER 4 12 F 3 Total perimeter in meters 9 gslnc250# 4 5 B - Poly internal id number 13 gslnc250-ID 4 5 B - Poly user id number 17 GSL-NAME 6 7 C 0 Soil number used to identify classification and relate to STATSGO tables GSLNC250.AAT Arc Attribute Table COLUMN ITEM NAME WIDTH OUTPUT TYPE DEC DESCRIPTION 1 FNODE# 4 5 B - From-node id of linear feature 5 TNODE# 4 5 B - To-node id of linear feature 9 LPOLY# 4 5 B - Left-side polygon id of linear feature 13 RPOLY# 4 5 B - Right-side polygon id of linear feature 17 LENGTH 4 12 F 3 Length of linear feature in meters 21 gslnc250# 4 5 B - Internal id number 25 gslnc250-ID 4 5 B - Internal id numberMap Unit Delineations are closed polygons that are generally geographic mixtures of groups of soils or soils and nonsoil areas.
NCCGIA Director, Karen Siderelis Database Administration, Zsolt Nagy Database Management, Ken Shaffer North Carolina Center for Geographic Information and Analysis Governor's Office Office of State Planning 301 North Wilmington Street, Suite 700 Raleigh, NC 27601-2825 U.S. Dept. of Agriculture, Natural Resource Conservation Service Fort Worth, TX
(919)733-2090 (voice)
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dataq@cgia.state.nc.us
STATSGO depicts information about soil features on or near the surface of the Earth. These data are collected as part of the National Cooperative Soil Survey.
U.S Department of Agriculture, Soil Conservation Service, unknown, multiple soil survey publications: U.S. Government Printing Office, Washington, D.C..
U.S Department of Agriculture, Natural Resource Conservation Service, unknown, multiple reconnaissance, county, and State general soil maps: U.S. Government Printing Office, Washington, D.C..
U.S. Geological Survey, unknown, multiple maps: U.S. Geological Survey, Reston, Virginia.
U.S Department of Agriculture, Soil Conservation Service, unknown, multiple compiled mylar overlays of map unit delineations, unpublished: unknown, unknown.
NC Center for Geographic Information and Analysis, 1988, State Plane projected digital data set: NC, Raleigh.
Data sources used in this process:
Data sources used in this process:
Person who carried out this activity:
(919) 733-2090 (voice)
(919)715-0725 (FAX)
dataq@cgia.state.nc.us
Data sources used in this process:
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. All attribute data conform to the attribute codes in the signed classification and correlation document and amendments and are current as of the date of digitizing.
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 accuracy 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.
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 to 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. The STATSGO map unit components are soil series
phases, and their percent composition represents the estimated
areal proportion of each within STATSGO 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 STATSGO 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 limits were established on the classification of
soils and the design and name of map units. These limits are
outlined in U.S. Department of Agriculture. 1975. Soil
Taxonomy A basic system of soil classification for making and
interpreting soil surveys. Soil Conserv. Serv., U.S. Dep.
Agric. Handb. 436.; U.S. Department of Agriculture. 1992. Keys
to Soil Taxonomy. SMSS Technical Monograph No. 19. Soil Surv.
Staff, Soil Conserv. Serv.; U.S. Department of Agriculture.
1993. National Soil Survey Handbook, title 430-VI. Soil Surv.
Staff, Soil 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.
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 inches.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- The U.S. Department of Agriculture, Natural Resource Conservation Service should be acknowledged as the data source in products derived from these data.
STATSGO was designed primarily for regional, multicounty, river basin, State, and multistate resource planning, management, and monitoring. STATSGO 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 Soil 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 STATSGO data are overlayed with other data layers, such as land use data, caution must be used in generating statistics on the co-occurrence of the land use data with the soil data. The composition of the STATSGO 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 STATSGO 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 maps 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.
Attribute data for some data elements may be incomplete or missing. Where data are unavailable, a mask should be used to exclude the area from analysis.
Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data.
(919) 733-2090 (voice)
(919) 715-0725 (FAX)
dataq@cgia.state.nc.us
Soils - NC General (STATSGO)
NCCGIA is charged with the development and maintenance of the State's corporate geographic database and, in cooperation with other mapping organizations, is committed to offering its users accurate, useful, and current information about the state. Although every effort has been made to ensure the accuracy of information, errors and conditions originating from physical sources used to develop the corporate database may be reflected in the data supplied. The client must be aware of data conditions and bear responsibility for the appropriate use of the information with respect to possible errors, original map scale, collection methodology, currency of data, and other conditions specific to certain data. NCCGIA does not support secondary distribution of this data. The use of trade names or commercial products does not constitute their endorsement by the NCCGIA or North Carolina State Government.
FOR DIGITAL OR NON-DIGITAL DATA, Contact NC CGIA, Data Distribution to order data, Phone 919.733.2090 ... Email dataq@cgia.state.nc.us ... Web Page order form <http://www.cgia.state.nc.us/cgdb/index.html>
For current FORMAT/MEDIA INFORMATION, use a web browser: <http://www.cgia.state.nc.us/cost.html> or phone NC CGIA Data Distribution 919.733.2090
Data creation and large data analysis jobs contact Database Administration P:(919)733-2090. All data is available through standard ordering procedures on a cost recovery basis.
All formats supplied are created using ARC/INFO GIS software on Unix workstations. Other formats are available. Format compatibility is the user's responsibility. For more information on formats and media, use a web browser: FORMAT/MEDIA INFORMATION - <http://www.cgia.state.nc.us/cost.html>
(919) 733-2090 (voice)
(919) 715-0725 (FAX)
dataq@cgia.state.nc.us