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Soils
- May 2007
OVERVIEW
The Soils datalayer has
been automated from 1:25,000 published soils surveys as provided on various
media by the United States Department of Agriculture (USDA) Natural
Resources Conservation Service (NRCS). All soils data released by MassGIS
have been "SSURGO-certified," which means they have been reviewed and approved
by the NRCS and meet all standards and requirements for inclusion in the
national release of county-level digital soils data. Soil survey areas
are roughly based on county boundaries.
At MassGIS the soils datalayer is
stored in ArcSDE for Oracle as the statewide feature class SOILS_POLY.
Two companion layers, SOILSPOT_PT and SOILSPOT_ARC, represent
"special" or "ad hoc" features such as gravel pits, wet areas, bedrock
escarpments and others.
Beginning in August, 2003, MassGIS
is distributing soils data online by survey area, not by USGS Quad (see
download links above). Specifics for each survey area (such as dates of
compilation and other details) can be found in the FGDC-compliant metadata
text files that MassGIS distributes with all SSURGO data.
The status for each survey area is
stored in the statewide layer named SOILSTAT_POLY. See details below
in the Attributes section.
View the
Status Map - Updated May 2007 for Hampden Central, Hampshire Central, and Worcester Northwest
This data set is not designed
for use as a primary regulatory tool in permitting or siting decisions,
but may be used as a reference source. This information 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 assign to the NRCS any authority
for the decisions that they will make. The NRCS will not perform any evaluations
of these maps for purposes related solely to state or local regulatory
programs.
Maps that use NRCS SSURGO data must
show the source (NRCS) and date and, space permitting, contain the following
notation:
"This Soil Survey Geographic (SSURGO)
data base was produced by the U.S. Department of Agriculture, Natural Resources
Conservation Service and cooperating agencies for the Soil Survey of _______
County, (state). The soils were mapped at a scale of ______ with
a _______ acre minimum size delineation. Enlargement of these maps to scales
greater than that at which they were originally mapped can cause misunderstanding
of the detail of mapping. If enlarged, maps do not show the small areas
of contrasting soil that could have been shown at a larger scale. The depicted
soil boundaries and interpretations derived from them do not eliminate
the need of onsite sampling, testing, and detailed study of specific sites
for intensive uses. Thus, this map and its interpretations are intended
for planning purposes only. Digital data files are periodically updated.
Files are dated, and users are responsible for obtaining the latest version
of the data."
Scale and minimum mapping unit
may be found in the FGDC-style metadata produced for each survey area
by NRCS. These metadata files may viewed at http://soildatamart.nrcs.usda.gov/Survey.aspx?State=MA. On this page, select a survey area and click the "View Metadata" button.
PRODUCTION
NRCS staff in Missouri and
Amherst, Mass. digitized and performed all quality control for data in
the Norfolk/Suffolk, Barnstable, Dukes, and Nantucket survey areas. All
other survey areas were developed by staff at the Massachusetts
Department of Agricultural Resources (DAR) and MassGIS, to which the
following description applies.
Source materials vary by survey area
and include scribecoat, clear film positives, and half-tone mylars containing
soil lines as well as labels and cultural features. Source sheets to date
contained data by "third-quad," a standard NRCS tiling scheme for its published
surveys which splits a USGS quadrangle into three sections (north, central
and south), "quarter-quad" (a USGS quad split into four (NW, NE, SW, SE)
parts, and full USGS quads. Scale varies by survey area; see the FGDC-compliant
metadata for each area distributed by MassGIS. (Note: the ArcSDE layer SOILINDEX_POLY is the index layer for the "third-quad" scheme.)
Source mylars were scanned at a resolution
of 500 dots per inch. The scanned images were registered, rectified, and
converted to grids using ARC/INFO. Soils linework was extracted from the
grids in the ARC/INFO GRID module and vectorized. MassGIS completed all
processing from scanning through vectorization. Map neatline development,
line smoothing, labeling, edge matching, and merging of third-quads into
full 7.5 minute quads was done by DAR staff. Special and ad hoc features
such as rock outcrops or stripped land areas that are smaller than the
original NRCS minimum mapping units were manually digitized by DAR. These
features were captured due to their uniqueness in their surroundings and
are represented as point and line data because they are too small to be
shown as area features at the scale of mapping. They are contained in the
SOILSPOT layers. Mass DAR staff performed all quality checking prior to
submittal for SSURGO certification. The NRCS Missouri Digitizing Unit reviewed
the soil coverages and special and ad hoc features for adherence to Soil
Survey Geographic (SSURGO) database standards.
EDITING
Checkplots were made by
DAR and reviewed by NRCS staff at various times during the editing process.
NRCS soil scientists edgematched each survey area to all abutting surveys
(including those in adjacent states) and these edits were incorporated
into the quad coverages. Mylar checkplots were provided to NRCS for compilation
of special and ad hoc features that were digitized by DAR staff. Each quad
within the survey area was submitted to the NRCS Missouri Digitizing Unit
for SSURGO review and these edits were incorporated in the final datalayer.
ATTRIBUTES
Soils Polygons
Each SOILS_POLY polygon contains the following
items:
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MUSYM |
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Map Unit symbol. Same as STATELEG
item (see below). This item is included in data distributed by NRCS from
the SSURGO Web site and uniquely identifies each closed delineation map
unit |
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MUKEY |
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Map Unit Key for linking information
in the National Soil Information System (NASIS) tables (presently used
for newer survey areas). This item is included in data distributed by NRCS
from the SSURGO Web site. |
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CODE |
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The soil map unit that appears
in
the published soil survey (hardcopy books). A map unit is identified
and named according
to the taxonomic classification of the dominant soil or soils. MassGIS
added this item to the attribute table. CODE values do not uniquely
identify a soil type statewide, only for a survey area. For example,
CODE ScB is STATELEG 16B in Essex North, but 223B in Norfolk-Suffolk.
Middlesex is unpublished and the CODE values for that survey area match
those in MUSYM. Worcester Northwest was published with the MUSYM codes.
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SS_AREA |
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Code for soil survey area (abbreviation of county name(s)):
| BARN |
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BARNSTABLE |
| BERK |
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BERKSHIRE |
| BRIS |
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BRISTOL SOUTH |
| BRISNO |
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BRISTOL NORTH |
| DUKES |
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DUKES |
| ESNOR |
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ESSEX NORTH |
| ESSOU |
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ESSEX SOUTH |
| FRAN |
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FRANKLIN |
| HAMDCE |
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HAMPDEN CENTRAL |
| HAMPCE |
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HAMPSHIRE CENTRAL |
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| HHEA |
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HAMPDEN-HAMPSHIRE EAST |
| HHWE |
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HAMPDEN-HAMPSHIRE WEST |
| MIDDSX |
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MIDDLESEX |
| NANTCK |
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NANTUCKET |
| NORSUF |
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NORFOLK-SUFFOLK |
| PLYMTH |
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PLYMOUTH |
| WONE |
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WORCESTER NORTHEAST |
| WONW |
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WORCESTER NORTHWEST |
| WORS |
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WORCESTER SOUTH |
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STATELEG |
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The corresponding code from the
statewide legend. Published soil surveys vary in coding schemes and the
statewide legend assigns one symbol to a soil map unit across the state.
Same as MUSYM. Added by MassGIS.
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SLOPE |
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Slope of the landscape, derived
from the last character of the STATELEG item, if present. Possible SLOPE codes are:
| A: 0-3% |
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B: 3-8% |
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C: 8-15% |
| D: 15-25% |
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E: 25-35% |
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0: Water or urban land (no slope) |
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SS_CODE |
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A unique value that contains both
the CODE and the soil survey area item (SS_AREA) as a redefined item. |
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MUSYM_AREA |
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Concatenation of MUSYM and
SS_AREA, to correlate the map unit symbol to its soil survey area. In
some cases, a mapunit may have different properties in different survey
areas. Usefule for some table joins.
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Special ("spot") Features
Each special/ad hoc feature (SOILSPOT_ARC and SOILSPOT_PT) contains the following items:
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LABEL |
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A three- or four-letter
code representing the special or ad hoc feature description; equal to the
FEATSYM or MUSYM item in data from NRCS. Current codes include:
| BLO |
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Blowout |
| BOU |
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Bouldery spot |
| CLA |
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Clay spot |
| DRY |
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Dry spot |
| ESB |
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Escarpment, bedrock |
| ESO |
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Escarpment, other |
| GPI |
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Gravel pit |
| GRA |
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Gravelly spot |
| GUL |
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Gully |
| LDF |
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Landfill |
| LVS |
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Levee |
| LVXR |
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Levee without road |
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| MAR |
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Marsh or swamp |
| MPI |
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Mine or quarry |
| ROC |
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Rock outcrop |
| SAN |
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Sandy spot |
| SLP |
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Short, steep slope |
| SNK |
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Sinkhole |
| SPO |
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Spoil Area |
| STN |
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Stony spot |
| STR |
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Stripped land |
| STV |
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Very stony spot |
| WET |
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Wet spot |
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MAJOR |
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A numeric code representing
a feature category based on USGS major code categories. |
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MINOR |
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USGS/NRCS codes that define
nodes, areas, lines, and points. |
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SS_AREA |
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Abbreviation of the survey area |
Soils Project Status
The SOILSTAT_POLY attribute
table contains the following items storing status information for each
survey area:
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SS_AREA |
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Abbreviation of the survey area |
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SURVEY_AREA |
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Full survey area name |
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COUNTY |
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County name (the survey area may
comprise part of a county) |
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STATUS |
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Status code |
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STATUS_DESC |
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Status description |
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Current STATUS and STATUS_DESC values include:
SC - SSURGO CERTIFIED (Available for disribution) FR - FIELD REMAPPING UNDERWAY
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METADATA |
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Format of related tables, as distributed on CD or available from online download:
A = Microsoft Access databases (newer survey areas) (All surveys with SSURGO-Certified data are coded "A"; those null are not yet available)
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Prime Farmland Soils
In ArcSDE, MassGIS has created the spatial view SOILS_POLY_PRIMEFARMLAND, based on the FARMLNDCL field in the SOILS_POLY_MAPUNIT table. Categories of prime farmland include:
All Areas Are Prime Farmland
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Land
that has the best combination of physical and chemical characteristics
for producing food, feed, forage, fiber, and oilseed crops, and is also
available for these uses (the land could be cropland, pastureland,
rangeland, forest land, or other land, but not urban built-up land or
water). For a full definition, see http://soils.usda.gov/technical/handbook/contents/part622.html#04.
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Farmland of Unique Importance
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Land
other than prime farmland that is used for the production of specific
high value food and fiber crops. Examples of such crops are citrus,
tree nuts, olives, cranberries, fruit, and vegetables.
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Farmland of Statewide Importance
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This
is land, in addition to prime and unique farmlands, that is of
statewide importance for the production of food, feed, fiber, forage,
and oil seed crops, as determined by the appropriate state agency or
agencies. Generally, these include lands that are nearly prime farmland
and that economically produce high yields of crops when treated and
managed according to acceptable farming methods.
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For full defnitions of these categories see Section 657.5 -- Identification of Important Farmlands on http://soils.usda.gov/technical/handbook/contents/part622.html.
To create this theme using shapefiles or personal geodatabase feature
classes, join SOILS_POLY to SOILS_POLY_MAPUNIT on the MUSYM_AREA field
and display on FARMLNDCL.
RELATED DATABASE TABLES
These tables are contained in Microsoft Access 2000 databases
(one for each available survey area) created by NRCS and which conform to the SSURGO II National Soil Information System (NASIS)
attribute structure. This attribute database gives the
proportionate
extent of the component soils and the properties for each soil. The
database 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 Access databases are available by clicking on the "Soils Polygons
and Special (Spot/Ad Hoc) Features" download link at the top of this
page (this will take you to the download page, and the Access databases
are listed in the "Metadata" column). The databases are also
distributed on
MassGIS
Data Viewer CDs. When the Access databases are first opened, a Soil
Reports form appears that allows the user to quickly query the database
and create a report for that survey area. For descriptiions of the
Access tables, see the "SSURGO Metadata" reports inside each Access
database.
For a list of all the tables in the Access databases see http://nasis.usda.gov/documents/metadata/ssurgo2_0/ssurgo20tr.pdf.
In the ArcSDE database internal to EOEA, combined tables exist for the following relational tables:
Table Name
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Description |
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What it Contains |
| SOILS_POLY_COMPONENT |
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Map Unit Component |
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Lists the map unit components identified in the referenced map unit, and selected properties of each component. |
| SOILS_POLY_COCROPYLD |
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Component Crop Yield
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Lists commonly grown crops and
their expected range in yields when grown on the referenced map unit
component. Yields for the map unit as a whole are given in the Mapunit
Crop Yield table (SOILS_POLY_MUCROPYLD).
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| SOILS_POLY_COFORPROD |
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Component Forest Productivity |
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Lists the site
index and the annual productivity in cubic feet per acre per year
(CAMI) of forest overstory tree species that typically occur on the
referenced map unit component. |
| SOILS_POLY_COHYDRICCRITERIA |
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Component Hydric Criteria |
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Lists the hydric soil criteria met for those referenced map unit components that are classified as a "hydric soil." |
| SOILS_POLY_COINTERP |
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Component Interpretation |
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Lists the predictions of behavior and limiting features for specified uses made for the referenced map unit component. |
SOILS_POLY_COMONTH
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Component Month
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Lists
the monthly flooding and ponding characteristics for the referenced map
unit component. This table has one row for each month of the year for
each component key.
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| SOILS_POLY_COPWINDBREAK |
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Component Potential Windbreak |
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Lists
the windbreak plant species commonly recommended for the referenced map
unit component. A windbreak plant listed in this table may be used
alone or in combination with other plants.
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| SOILS_POLY_CORESTRICTIONS |
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Component Restrictions
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Lists the root restrictive feature(s) or layer(s) for the referenced map unit component. |
| SOILS_POLY_COSOILMOIST |
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Component Soil Moisture
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Describes the typical soil
moisture profile for the referenced map unit component during the month
referenced in the Component Month table. The soil moisture profiles for
each month, taken as a group of twelve months, describe the
representativesituation for the component throughout the year. |
SOILS_POLY_COTREESTOMNG
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Component Trees To Manage |
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Lists the trees commonly recommended for managing on the referenced map unit component. |
| SOILS_POLY_MAPUNIT |
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Mapunit |
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Identifies the map units included in the referenced legend. Data related the map unit as a whole are also given. |
SOILS_POLY_MAPUNIT2
[ Download .dbf ]
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Mapunit and description
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Map unit (MUSYSM) and map unit
description (MUNAME) for all unique map units across the state; this
table was created by MassGIS for use in the Data Viewer and OLIVER
mapping applications.
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| SOILS_POLY_MUAGGATT |
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Mapunit Aggregated Attribute
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Records
a variety of soil attributes and interpretations that have been
aggregated from the component level to a single value at the map unit
level. They have been aggregated by one or more appropriate means in
order to express a consolidatedvalue or interpretation for the map unit as a whole.
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| SOILS_POLY_MUCROPYLD |
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Mapunit Crop Yield
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Lists
commonly grown crops and their expected yields for the referenced map
unit as a whole. Yields for individual map unit components are given in
the Component Crop Yield table (SOILS_POLY_COCROPYLD).
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SOILS_POLY_MUTEXT
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Mapunit Text
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Notes and narrative descriptions related to the referenced map unit.
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These additional non-relational tables
provide further information:
| SOILS_POLY_CODES |
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Database codes |
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Stores information on all codes
used in the database |
| SOILS_POLY_LEGEND |
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Summary information on all available survey areas |
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Survey area names, codes, total acreage, scale of data development |
| SOILS_POLY_MDSTATTABS |
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Table Static Metadata
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Records
metadata (names, descriptions, etc.) about the tables that make up the
tabular data set in each Access database. Each record in this table
represents onetable
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| SOILS_POLY_MDSTATTABCOLS |
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Table Column Static Metadata
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Table
records the metadata for all columns of all tables that make up the
tabular data set. Each record in this table represents one column of a
particular table.
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The following table provides descriptions
of the codes used in the SOILSPOT layers:
| SOILS_POLY_FEATURE |
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Special feature codes |
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Stores information on all codes
used in the 'LABEL' item in the SOILSPOT arc and point layers. |
For lists and descriptions of all the tables and the
codes in the SSURGO 2 database, please refer to the SSURGO Metadata PDF documents "Tables", "Table Columns", "Table Column Descriptions", and "Domains".
WHAT MassGIS DISTRIBUTES
On
MassGIS Data Viewer CDs,
soils polygons and special features are included in Shapefile format
for
available areas in the 'Physical_Resources' folder. In the 'soilmeta'
sub-folder are the NASIS-formatted related tables
for all available survey areas, in Microsoft Access
2000 databases inside self-extracting executables. These NASIS tables
may
be used to produce reports and generate thematic soils maps, and are
necessary for use with NRCS' Soil Data Viewer product (see the next
section, Displaying the Data). Additionally, users may download data and metadata
from the links at the top of this page.
DISPLAYING THE DATA
The
soils polygons have very few attributes. To decipher the many ways in
which the soils data may be interpreted and displayed, using the many related database tables (listed above), USDA/NRCS has
developed the Soil Data Viewer, software that may be run in GIS or
non-GIS mode. It works on one survey area at a time. To create
soils-based thematic maps (in GIS mode) with the Viewer, users need
ArcView 3.1+, and any of the downloadable
.mdbs and shapefiles from MassGIS. The software in GIS mode is accessible as an ArcView
Extension; it is a stand-alone utility in non-GIS mode. Users may
create text reports in both modes. See http://www.itc.nrcs.usda.gov/soildataviewer/
for download, installation, and user guide information. The software also may be downloaded from the MassGIS ftp site (31 MB .zip file, including installation and user guides).
NRCS has also released versions of the Soil Data Viewer for ArcGIS 8.3 and 9.0. See http://soildataviewer.nrcs.usda.gov/
and click on "Download and Install Soil Data Viewer" on the right side
of the page. NRCS notes that the application for ArcMap 9.0 (Soil Data
Viewer 5.1) has now been verified to work under ArcGIS 9.1 where no
service pack or service pack 1 is installed. MassGIS has not tested
this under ArcMap 9.1 or 9.2.
Also, NRCS has an online soils viewer ("Web Soil Survey") that displays
a number of user-specified characteristics of soils. See http://websoilsurvey.nrcs.usda.gov/app/.
MassGIS has created the SOILS_POLY_MAPUNIT2
table that may be joined to the polygon data on the MUSYM item; this
table provides descriptive text for each map unit and is useful for
identifying and labeling soils polygons.
MAINTENANCE
These datalayers are
maintained
by DAR and developed and updated when necessary in cooperation with
NRCS. Additional survey areas will be added as they become available.
Please see the current status map. In May, 2005, the five older survey
areas in Massachusetts (BARN, BERK, HHEA, HHWE, and NORSUF) became available as SSURGO II data with accompanying NASIS Access databases.
ADDITIONAL REFERENCES
Further information is available
in the form of documents produced and maintained by the NRCS. These documents
include:
- SSURGO Metadata - documents, diagrams and reports describing
the SSURGO standard, as well as the tools and procedures that are
necessary to effectively use this data, can be found at http://soildatamart.nrcs.usda.gov/SSURGOMetadata.aspx.
- The National Soil Survey Handbook,
a multi-chapter guide that provides the main operational and procedural
guidance for the soil survey program. All Handbook chapters are
viewable on the Web and available for download in Microsoft Word 6.0 format.
Please visit http://soils.usda.gov/technical/handbook/.
-
The Soil Survey Manual, a single
volume book which provides the major principles and practices needed for
making and using soil surveys and for assembling and using data related
to them. The Manual is intended primarily for use by soil scientists engaged
in the classification and mapping of soils and in the interpretation of
soil surveys. Although the Manual is oriented to the needs of those actively
engaged in preparing soil surveys for publication, workers and students
who have limited soils experience or are less familiar with the soil survey
process also will be able to use the information. The Manual may
be viewed in Microsoft Word and Adobe PDF formats on the web at http://soils.usda.gov/technical/manual/.
- The NASIS (National Soil Information System) Web site at http://nasis.usda.gov.
NASIS is a tool to help you create and maintain soil surveys. It takes
advantage of database technology to provide an automated means for
storing all information about soil surveys.
- Massachusetts Soil Survey - The Web site http://nesoil.com/massachusetts_soil_survey.htm contains information on Massachusetts soils surveys, including detailed descriptions of soil map units.
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