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.
Digital versions of hydrography, cultural features, and other associated layers that are not part of the SSURGO data set may be available from the primary organization listed in the Point of Contact.
publication date
Internal feature number. (Source: ESRI)
Feature geometry. (Source: ESRI)
Area Symbol - A symbol that uniquely identifies a single occurrence of a particualr type of area (e.g. Lancaster Co., Nebraska is NE109). (Source: U.S. Department of Agriculture, Natural Resources Conservation Service)
Spatial Version - A sequential integer number used to denote the serial version of the spatial data for a soil survey area. (Source: U.S. Department of Agriculture, Natural Resources Conservation Service)
Mapunit Symbol - The symbol used to uniquely identify the soil map unit in the soil survey. (Source: U.S. Department of Agriculture, Natural Resources Conservation Service)
Mapunit Key - A non-connatative string of characters used to uniquely identify a record in the Mapunit table. (Source: U.S. Department of Agriculture, Natural Resources Conservation Service)
Map Unit Delineations are closed polygons that may be dominated by a single soil or miscellaneous area component plus allowable similar or dissimilar soils, or they can be geographic mixtures of groups of soils or soils and miscellaneous areas. The map unit symbol uniquely identifies each closed map unit delineation. Each symbol corresponds to a map unit name. The map unit key is used to link to information in the National Soil Information System tables. Map Unit Delineations are described by the National Soil Information System database. 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 National Soil Information System database contains static metadata. It documents the data structure and includes such information as what tables, columns, indexes, and relationships are defined as well as a variety of attributes of each of these database objects. Attributes include table and column descriptions and detailed domain information. The National Soil Information System database also contains a distribution metadata. It records the criteria used for selecting map units and components for inclusion in the set of distributed data. Special features are described in the feature table. It includes an area symbol, feature label, feature name, and feature description for each special and ad hoc feature in the survey area.
Soil Taxonomy: A basic system of soil classification for making and interpreting soil surveys. Agricultural Handbook 436, 1999, USDA, SCS. Keys to Soil Taxonomy (current issue), USDA, SCS. National Soil Survey Handbook, Title 430-VI, part 647 (current issue), USDA, NRCS. Agricultural Handbook 18, Soil Survey Manual, 1993, USDA, SCS.
USDA - Natural Resources Conservation Service
Connecticut State Office
344 Merrow Road, Suite A
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.
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
information for soil map unit delineations, special soil feature locations, and data on soil properties
Hydrographic features to include double line streams and area features greater than 3 acres in size were subset from USGS 1:24000 scale Digital Line Graphs updated to 1985 and 1990 imagery by NRCS and used as a template for soils digitizing
base material for field mapping and soils/land use updates
base material for field mapping and soils/land use updates
digitizing source
base material for compilation - original orthophotoquad scale 1:24000
digital base material for 1:12000 review
SSURGO data for revision of spatial data
attribute (tabular) information
Includes all soil polygon features for Connecticut in Shapefile format.
Includes all soil polygon features for Connecticut in GeoDatabase feature format.
Field procedures for the second order soil survey included plotting of soil boundaries determined by field observation and by interpretation of remotely sensed data. Boundaries were verified at closely spaced intervals, and the soils in each delineation were identified by traversing and transecting the landscape. The classification and map unit names were progressively reviewed December 1993 and August 2001.
Hartford County, Connecticut, had a previously published soil survey, 1962, at a scale of 1:20000. Landuse was updated to 1990, limited mapping was performed in areas where significant changes in classification occurred, and mapunits were correlated to the Connecticut legend.
New London County, Connecticut, had a previously published soil survey, 1983, at a scale of 1:15840. Landuse was updated to 1985/1986. Mapunits were correlated to the Connecticut legend. Small mapunits less than 3 acres and narrow drainage ways may have been combined with adjacent units.
Tolland County, Connecticut, had a previously published soil survey, 1966, at a scale of 1:15840. The original survey was developed mainly for agricultural interpretations, therefore, wooded areas were not mapped as detailed as open areas. Approximately 75% of the county was remapped to current standards during the period from 1985 to 1994. The new data was published in 1996. Mapunits were correlated to the Connecticut legend.
Windham County, Connecticut, had a previously published soil survey, 1981, at a scale of 1:15840. Landuse was updated to 1985/1986. Mapunits were correlated to the Connecticut legend. Small mapunits less than 3 acres and narrow drainage ways may have been combined with adjacent units.
Fairfield County, Connecticut, had a previously published soil survey, 1981, at a scale of 1:15840. Landuse was updated to 1990. Mapunits were correlated to the Connecticut legend. Small mapunits less than 3 acres and narrow drainage ways may have been combined with adjacent units.
New Haven County, Connecticut, had a previously published soil survey, 1979, at a scale of 1:15840. Landuse was updated to 1990. Mapunits were correlated to the Connecticut legend. Small mapunits less than 3 acres and narrow drainage ways may have been combined with adjacent units.
Middlesex County, Connecticut, had a previously published soil survey, 1980, at a scale of 1:15480. Landuse was updated to 1990, limited mapping was performed in areas where significant changes in classification occurred, and mapunits were correlated to the Connecticut legend.
Litchfield County, Connecticut, had a previously published soil survey, 1970, at a scale of 1:15840. The original survey was developed mainly for agricultural interpretations, therefore, wooded areas were not mapped as detailed as open areas. Approximately 75% of the county was remapped to current standards during the period from 1994 to 2001. Mapunits were correlated to the Connecticut legend.
Hydrography was transferred from 1:15840 acetates to the 1:15840 orthophotographs as a reference only for soil delineations. This data was not digitized from the orthophotographs, but digitally subset from USGS DLGs. Field maps and published atlas sheets were ratioed to approximately 1:15840 when necessary and then manually compiled using imagery transfer techniques to 1:15840 orthophotograph enlargements. Slight adjustments were made to soil boundaries near hydrography for clarity. These adjustments occurred along narrow floodplains, shorelines, and other areas of fluctuating water levels. Water bodies for Litchfield County were adjusted from the aerial photography during remapping. Special soil features were compiled on film overlays and manually digitized using GRASS 4.1.3 and ArcInfo 8.2. Soil delineations were digitized using one of the following procedures: 1) Soil delineations were inked on 7mil overlays and scanned at 300dpi. Utilizing ProVec software, data were edited and converted to vector format. Data was then imported into ARC/INFO 3.4D and georeferenced to Connecticut State Plane feet - NAD 27. Each quadrangle has sixteen tics, therefore, data was transformed by ninths maintaining Root Mean Square (RMS) less than .003. The hydrography template was imported, vectors edited and labels created. 2) Soil delineations were manually digitized using ARC/INFO 3.2.1. Data were registered in Connecticut State Plane coordinates maintaining RMS less than .003. Weed and fuzzy tolerances maintained at 3. Data were transferred to ARC/INF0 6.0 for approximate edgematching and label editing, exported to DLGs, and imported to GRASS 4.1.3. Data was projected to UTM coordinates NAD 27 and edited for node to node edgematching. Soil special features were manually digitized by using one of the following software products, GRASS 4.1.3 or ArcInfo 8.2. Compilation, digitizing, and quality control were performed by soil scientists and cartographic technicians at the Connecticut Natural Resources Conservation Service. Digital scanning and vector conversion was performed by private contractor. Digital editing was performed at the Connecticut Natural Resources Conservation Service and the Connecticut Department of Environmental Protection - Natural Resources Center. Digital soils delineations were visually verified using background digital orthophotograph imagery at 1:12000 to ensure accuracy at this scale. Organic soils, bedrock controlled soils and other easily identified features were utilized to ensure vertical integration and accurate soil delineation placement. Digital review for adherence to SSURGO standards was performed by the Missouri NRCS Digitizing Unit. Edits were made in ArcEdit. The survey area boundary was replaced with the boundary arcs from adjacent surveys, where possible. A new ARC/INFO coverage reflecting these edits was produced and reviewed for adherence to SSURGO standards by Missouri NRCS Regional Digitizing Unit staff. The certified data were uploaded to the Soil Data Warehouse for archiving and distribution.
The National Soil Information System data base was developed by Natural Resources Conservation Service soil scientists according to national standards.
The previously certified digital data of the Connecticut Statewide Update, Subset 1, were updated for incorporation into the Connecticut statewide survey. Boundaries were replaced with the boundary arcs from adjacent subsets of Connecticut as well as other adjacent surveys. The updated data were incorporated into the statewide digital data, and a new ARC/INFO coverage reflecting these edits was produced with ARC/INFO 7.2.1 and reviewed for adherence to SSURGO standards by Missouri NRCS Regional Digitizing Unit staff.
The Natural Resources Conservation Service State Soil Scientist or delegate, upon completion of data quality verification, determined that the tabular data should be released for official use. A selected set of map units and components in the soil survey legend was copied to a staging database, and rating values for selected interpretations were generated. The list of selected interpretations is stored in the database table named sainterp.
The Natural Resources Conservation Service State Soil Scientist or delegate verified that the labels on the digitized soil map units link to map units in the tabular database, and certified the joined data sets for release to the Soil Data Warehouse. A system assigned version number and date stamp were added and the data were copied to the data warehouse. The tabular data for the map units and components were extracted from the data warehouse and reformatted into the soil data delivery data model, then stored in the Soil Data Mart. The spatial data were copied to the Soil Data Mart without change.
The tabular data were extracted from the data mart without change. The spatial data's coordinate system was transformed to UTM Zone 18, Northern Hemisphere (NAD 83) using ESRI ArcObjects 8.3 "ConvertFeatureClass" and exported to an ESRI shapefile. ESRI ArcInfo/Workstation 8.3 was used to read the shapefile, clean the double precision cover with a dangle length of 0.000001 and a fuzzy tolerance of 0.000001. The cover was written out as an interchange file without blank compression.
Interchange file named smu_a_ct600.e00 was downloaded from the U.S. Department of Agriculture, Natural Resources Conservation Service website. Using ArcInfo Workstation software, the interchange file was imported to ArcInfo coverage format and converted from UTM Zone 18, North American Hemisphere (NAD83) to Connecticut State Plane Coordinate System (NAD83). Name of resulting coverage was SOIL_POLY. Polygon and feature topology was established for SOIL_POLY coverage using the ArcInfo Workstation BUILD command. Metadata was imported from soil_metadata_ct600.xml file using ArcCatalog software. Metadata was edited to include attribute definitions for the following polygon attributes: AREASYMBOL, SPATIALVER, MUSYM, and MUKEY. These definitions are from the SSURGO Metadata - Table Column Descriptions document published by the U.S. Department of Agriculture, Natural Resources Conservation Service.
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Export to Shapefile Format - Converted polygon feature data from ArcInfo Coverage named SOIL_POLY to a Shapefile named Soils_Poly.shp. Excluded the AREA, PERIMETER, SOIL_POLY#, SOIL_POLY-ID attributes from the Shapefile because their values are only maintained by ArcInfo software with data that is in ArcInfo Coverage format.
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Convert to GeoDatabase Feature Class format - Defined new Feature Class named Soils_Poly; and imported the attribute definitions, loaded features and imported metadata from Soils_Poly.shp shapefile. Spatial Reference Properties for Feature Class: Coordinate System: NAD_1983_StatePlane_Connecticut_FIPS_0600_Feet XY Domain MinX: 100000; MaxX: 2247483.645 XY Domain MinY: 200000; MaxY: 2347483.645 Precision: 1000
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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 amendment(s).
The accuracy of these digital data is based upon their compilation to base maps that meet National Map Accuracy Standards at a scale of 1 inch equals 1,000 feet. 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. 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 in terms of their soil components or miscellaneous areas or both. Each map unit differs in some respect from all others in a survey area and each map unit has a symbol that uniquely identifies the map unit on a soil map. Each individual area, point, or line so identified on the map is a delineation. Soil Scientists identify small areas of soils or miscellaneous areas that have properties and behavior significantly different than the named soils in the surrounding map unit. These minor components may be indicated as special features. If they have a minimal effect on use and management, or could not be precisely located, they may not be indicated on the map. A map unit has specified kinds of soils or miscellaneous areas (map unit components), each with a designated range in proportionate extent. Map units include one or more kinds of soil or miscellaneous area. Miscellaneous areas are areas that have little or no recognizable soil. Specific National Cooperative Soil Survey standards and procedures were used in the classification of soils, design and name of map units, and location of special soil features. These standards are outlined in Agricultural Handbook 18, Soil Survey Manual, 1993, USDA, NRCS; Agricultural Handbook 436, Soil Taxonomy, 1995, USDA, NRCS; and all Amendments; Keys to Soil Taxonomy, (current issue) USDA, NRCS; National Soil Survey Handbook, title 430-VI,(current issue) USDA, NRCS. The actual composition and interpretive purity of the map unit delineations were based on data collected by scientists during the course of preparing the soil maps. 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 use a single name from the dominant component in the map unit. Dissimilar components are minor in extent. The soil component in a consociation may be identified at any taxonomic level. Soil series is the lowest taxonomic level. A consociation that is named as a miscellaneous area is dominantly that kind of area and minor components do not significantly affect the use of the map unit. 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 consist of two or more dissimilar components that occur in a regularly repeating pattern. The total amount of other dissimilar components is minor extent. The following arbitrary rule determines whether complex or association is used in the name. The major components of an association can be separated at the scale of mapping. In either case, because the major components are sufficiently different in morphology or behavior, the map unit cannot be called a consociation. In each delineation of 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 are not consistently associated geographically and, therefore, do not always occur together in the same map delineation. These components are included in the same named map unit because their use and management are the same or very similar for common uses. Generally they are grouped together because some common feature, such as steepness, stoniness, or flooding, determines their use and management. If two or more additional map units would serve no useful purpose, they may be included in the same unit. Each delineation has at least one of the major components, and some may have all of them. The same principles regarding the proportion of minor components that apply to consociations also apply to undifferentiated groups. The same principles regarding proportion of inclusion 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. 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 3 acres.
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 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). Edge locations generally do not deviate from centerline to centerline by more than 0.01 inch. The Soil Survey of Connecticut is bordered on the north by the State of Massachusetts; to the east by the State of Rhode Island; to the south by Long Island Sound and to the west by the State of New York. Feature edges in this soil survey are not matched to those in Westchester County, New York, Putnam County, New York, Dutchess County, New York, Berkshire County, Massachusetts, Hampden and Hampshire Counties, Western Part, Massachusetts, Hampden and Hampshire Counties, Eastern Part, Massachusetts, and the State of Rhode Island soil surveys. Acceptable joins as outlined in Revisions to the National Soils Handbook, dated 8/27/97 were achieved with all of the surrounding surveys. Feature labels do not always match, but soil interpretations are similar enough to achieve an acceptable join. Map units in this survey that join map units in adjacent surveys share a common component, common stoniness class, and common slopes. Differences across state lines occurred relative to map unit design and scales used in mapping. Typically, map units designed for a scale of 1:12000 are comprised of consociations, complexes, and undifferientiated units. Complexes and undifferentiated units are comprised of two or more components. In areas where these complexes or undifferentiated units join a consociation (one named component), this is an acceptable join if the adjoining map units share a common component, common stoniness class, and common slopes thus resulting in similar soil interpretations. An exception is made for adjoining organic soils, which are considered to match. The scale is used to determine how much detail can be shown on the map. To deal with the limitations of scale, some map units were designed to cover two stoniness classes and two slope classes. Where map units that are very stony join extremely stony, they will be considered a acceptable join since each stoniness class is commonly an inclusion in the other during the mapping process. Non-stony map units must match non-stony map units. Overlapping slope ranges will be considered as matching.
The U.S. Department of Agriculture, Natural Resources Conservation Service, should be acknowledged as the data source in products derived from these data. This data set is not designed for use as a primary regulatory tool in permitting or citing 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. Photographic or digital enlargement 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. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data.
501 West Felix Street, Building 23, P.O. Box 6567
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, for damage, for transmission of viruses, or for computer contamination through the distribution of these data sets. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status. (Not all prohibited bases apply to all programs.)
| Data format: | spatial in format ArcView shapefile Size: 323.077 |
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| Network links: | URL:http://SoilDataMart.nrcs.usda.gov/ |
| Data format: | spatial in format ARC/INFO coverage Size: 323.077 |
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| Network links: | URL:http://SoilDataMart.nrcs.usda.gov/ |
| Data format: | spatial in format ARC/INFO interchange file Size: 323.077 |
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| Network links: | URL:http://SoilDataMart.nrcs.usda.gov/ |
| Data format: | keys and attributes in format ASCII Size: 323.077 |
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| Network links: | URL:http://SoilDataMart.nrcs.usda.gov/ |
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.
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| Data format: | spatial in format Esri Feature Class |
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| Network links: | http://www.ct.gov/deep |
USDA - Natural Resources Conservation Service
Connecticut State Office
344 Merrow Road, Suite A