STATSGO Metadata - Alaska
Identification Information
Citation:
Originator: U.S. Department of Agriculture, Natural Resource
Conservation Service
Publication Date: 1979
Title: Exploratory Soil Survey of Alaska; STATSGO Publication
Publication Place: Fort Worth, Texas
Publisher: U.S. Department of Agriculture, Natural
Resource Conservation Service
Description
Abstract: This data set consists of georeferenced digital map and
attribute data derived from the publication "Exploratory Soil Survey
of Alaska". The map is 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 1:1,000,000 scale.
The original linework was drawn and verified in the field using 1
by 3 degree topographic quadrangles as the mapping base. Linework
from these basemaps was digitized and merged to form a seamless
statewide coverage. Soil map units are linked to attributes in the
Map Unit Interpretations Record relational data base which gives the
proportionate extent of the component soils and their properties.
Purpose: 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.
Time Period of Content
Single Date/Time Calendar Date: 1995
Currentness Reference: publication date
Status
Progress: Complete
Maintenance and Update Frequency: As needed
Spatial Domain
Bounding Coordinates
West Bounding Coordinate: 172.0
East Bounding Coordinate: -129.0
North Bounding Coordinate: 72
South Bounding Coordinate: 51
Keywords
Theme
Theme Keyword Thesaurus: None
Theme Keyword: Soils
Theme Keyword: General Soils Map
Theme Keyword: Exploratory Soil Survey
Theme Keyword: State Soil Geographic
Theme Keyword: STATSGO
Place
Place Keyword Thesaurus: Counties and County Equivalents of the
United States and the District of Columbia (FIPS Pub 6-3)
Place Keyword: Alaska (02)
Access Constraints: None
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.
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
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 STATSGO data 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 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.
The minimum area depicted is approximately 10,000 acres. The total
number of delineations is 2310. 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. If files are dated
users are responsible for obtaining the latest version of the
data.
Point of Contact
Contact Organization Primary
Contact Organization: U.S. Department of Agriculture, Natural
Resources Conservation Service
Contact Position: State Soil Scientist
Contact Address
Address Type: mailing address
Address: 949 E. 36'th Avenue, Suite 400
City: Anchorage
State or Province: Alaska
Postal Code: 99508-4362
Contact Voice Telephone: 907 271 2424
Contact Facsimile Telephone: 907 271 3951
Data Quality Information
Attribute Accuracy
Attribute Accuracy Report: 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.
Logical Consistency Report: 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. 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).
Completeness Report: 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 three components. The STATSGO map
unit components are soil subgroup 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 random transect and remote sensing of
landforms and vegetation patterns.
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.
Positional Accuracy
Horizontal Positional Accuracy
Horizontal Positional Accuracy Report: 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 mountains to a floodplain, the
transition will be very narrow. Soil delineation boundaries were
digitized within 0.01 inches of their locations on the digitizing
source.
Lineage
Source Information
Source Citation
Originator: U.S Department of Agriculture, Natural Resources
Conservation Service
Title: Exploratory Soil Survey of Alaska
Geospatial Data Presentation Form: map
Publication Information
Publication Place: Washington, D.C.
Publisher: U.S.Government Printing Office
Source Scale Denominator:1,000,000
Type of Source Media: paper
Source Currentness Reference: publication date
Source Time Period of Content: 1979
Abbreviation: NRCS1
Source Contribution: base information for development of
map unit delineations and transect data for naming map units.
Source Citation
Originator: U.S. Geological Survey
Title: multiple maps
Geospatial Data Presentation Form: map
Publication Information
Publication Place: Reston, Virginia Publisher: U.S.
Geological Survey Source Scale Denominator: 250000
Type of Source Material: stable-base material
Source Currentness Reference: unknown
Source Citation Abbreviation: USGS1
USGS1 Source Contribution: base materials for compilation of
map unit delineation linework
Source Citation
Originator: U.S Department of Agriculture, Soil Conservation
Service
Title: multiple compiled mylar overlays of map unit delineations,
unpublished
Geospatial Data Presentation Form: annotated overlay
Type of Source Media: stable-base material
Source Currentness Reference: unknown
Source Citation Abbreviation: NRCS2
Source Contribution: digitizing source
Process Step
Process Description: Map unit composition was determined by
referencing the narrative map unit descriptions in the
"Exploratory Soil Survey of Alaska".
Source Used Citation Abbreviation: NRCS1
Process Date: 1994
Process Step
Process Description: Soil map unit lines and symbols were drafted
in red pencil on a mylar overlay that was punch registered to fit
the mylar USGS 1:250,000-scale topographic quadrangle. A
detailed and complete edit was performed on all overlays before
digitizing. The soil delineation overlays were raster scanned at
a scanning resolution of at least 0.01 inches and converted to a
vector format or were manually digitized on a digitizing tablet
with a resolution of at least 0.001 inches. Four control points
corresponding to the four corners of the quadrangles were used
for registration during data collection. The control points were
either explicitly entered or developed by the software. The data
sets were edge matched and merged into statewide coverages. A
detailed and complete edit was performed on all digital data.
Source Used Citation Abbreviation: USGS1, NRCS2
Process Date: 1994
Spatial Data Organization Information
Direct Spatial Reference Method: Vector
Spatial Reference Information
Horizontal Coordinate System Definition
Planar Grid Coordinate System Name: Albers Conical Equal Area
Standard Parallel 1: 55
Standard Parallel 2: 65
Longitude of Central Meridian: -154
Latitude of Projection Origin: 50.0
False Easting: 0.0
False Northing: 0.0
Planar Coordinate Information
Planar Coordinate Encoding Method: coordinate pair
Coordinate Representation
Abscissa Resolution: 6.35
Ordinate Resolution: 6.35
Distance Units: meters
Geodetic Model
Horizontal Datum Name: North American Datum of 1927 Ellipsoid
Name: Clarke 1866
Semi-major Axis: 6378206.4
Denominator of Flattening Ratio: 294.9786982
Entity and Attribute Information
Overview Description
Entity and Attribute Overview: Map Unit Delineations are closed
polygons that are generally geographic mixtures of groups of soils
or soils and nonsoil areas.
The map unit ID uniquely identifies each closed delineation, map
unit. Each map unit ID is linked to a map unit name. The map unit
ID is also the key for linking information in the Map Unit
Interpretations Record tables.
Map Unit Delineations are described by the Map Unit Interpretations
Record data base. This attribute data base gives the proportionate
extent of the component soils and the properties for each soil. The
data base contains both estimated and measured data on the physical
and chemical soil properties and soil interpretations for
engineering, water management, recreation, agronomic, woodland,
range and wildlife uses of the soil.
The Soil Map Unit Interpretations
Record data base consist of the following relational tables:
codes (data base codes) - stores information on all codes
used in the data base
comp (map unit component) - stores information which will
apply to a specific component of a soil map unit
compyld(component crop yield) - stores crop yield
information for soil map unit components
forest (forest understory) - stores information for plant
cover as forest understory for soil map unit components
interp(interpretation) - stores soil interpretation ratings
(both limitation ratings and suitability ratings) to
soil map unit components
layer (soil layer) - stores characteristics which apply to
soil layers for soil map unit components
mapunit (map unit) - stores information which applies to
all components of a soil map unit
plantcom (plant composition) - stores plant symbols and
percent of plant composition associated with components of
soil map units
plantnm (plant name) - stores the common and scientific
names for plants used in the data base
rsprod (range site production) - stores range site
production information for soil map unit components
taxclass (taxonomic classification) - stores the taxonomic
classification for soils in the data base
windbrk (windbreak)- stores information on recommended
windbreak plants for soil map unit components
wlhabit(wildlife habitat) - stores wildlife habitat
information for soil map unit components
woodland (woodland) - stores information on common indicator
trees for soil map unit components
woodmgt (woodland management) - stores woodland management
information for soil map unit components
yldunits (yield units) - stores crop names and the units
used to measure yield.
Entity and Attribute Detail Citation
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.
U.S. Department of Agriculture. 1993. Soil Survey Manual. Soil
Surv. Staff, U.S. Dep. Agric. Handbook 18.
U.S. Department of Agriculture. 1994. State Soil Geographic
(STATSGO) Data Base: Data use information. Soil Conserv. Serv.
U.S. Department of Agriculture. State Soil Survey Database Data
Dictionary. Soil Conserv. Serv.
Distribution Information
Distributor
Contact Organization Primary
Contact Organization: U.S. Department of Agriculture, Soil
Conservation Service, National Cartography and GIS Center
Contact Address
Address Type: mailing address
Address: P.O. Box 6567
City: Fort Worth
State or Province: Texas
Postal Zone: 76115
Contact Voice Telephone: 817 334 5559
Contact Facsimile Telephone: 817 334 5469
Resource Description: Alaska STATSGO
Distribution Liability: Although these data 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.)
Standard Order Process
Non-digital Form: Not available
Digital Form
Digital Transfer Information
Format Name: DLG
Format Date: 19960101
Format Specification:
Optional Format Content Information: spatial and keys
Transfer Size: 13 megabytes
Digital Form
Digital Transfer Information
Format Name: ASCII
Format Content Information: keys and attributes
Transfer Size: unknown
Digital Form
Digital Transfer Information
Format Name: ARCE
Format Content Information: spatial, keys, and attributes
Format Specification: Single precision Transfer
Size: unknown
Digital Transfer Option
Offline Option
Offline Media: 8mm cartridge tape Recording Capacity
Recording Density: 2.3 Recording Density Units: gigabytes
Recording Format: tar
Digital Transfer Option
Offline Option
Offline Media: 1/4-inch cartridge tape Recording Capacity
Recording Density: 150 Recording Density Units: megabytes
Recording Format: tar
Fees: The charge for one data set is $500.00. A data set is one
state in a state-wide format and includes both spatial and attribute
data.
Ordering Instructions: Call or write to organizations listed under
Distributor. Spatial line data are in DLG-3 optional or ARC Export
formats. Digital line graph files contain major and minor code
pairs in area and line records. A conversion legend is provided for
each digital line graph file. Map unit IDs are available in a
companion ASCII attribute file. The Map Unit Interpretations Record
attribute soil data are available in variable length, tab delimited,
ASCII or ARC Export files.
Turnaround: 10 working days
Metadata Reference Information
Metadata Date:1/29/96
Metadata Review Date:1/96
Metadata Future Review Date: as needed
Metadata Contact: State Soil Scientist
Contact Organization
Primary Contact Organization: U.S. Department of Agriculture,
Natural Resources Conservation Service
Contact Position: State Soil Scientist
Contact Address:
Address Type: mailing address
Address: 949 E. 36'th, Suite 400
City: Anchorage
State or Province:Alaska
Postal Code: 99508-4362
Contact Voice Telephone: 907-271-2424
Metadata Standard Name: Content Standards for Digital Geospatial
Metadata Metadata Standard Version:
This information is being shared as a prototype and may not reflect current updates
to the database.
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