These data depict the western United States Map Unit areas as defined by the USDA NRCS. Each Map Unit area contains information on a variety of soil properties and interpretations. The raster is to be joined to the .csv file by the field "mukey." We keep the raster and csv separate to preserve the full attribute names in the csv that would be truncated if attached to the raster. Once joined, the raster can be classified or analyzed by the columns which depict the properties and interpretations. It is important to note that each property has a corresponding component percent column to indicate how much of the map unit has the dominant property provided. For example, if the property "AASHTO Group Classification (Surface) 0 to 1cm" is recorded as "A-1" for a map unit, a user should also refer to the component percent field for this property (in this case 75). This means that an estimated 75% of the map unit has a "A-1" AASHTO group classification and that "A-1" is the dominant group. The property in the column is the dominant component, and so the other 25% of this map unit is comprised of other AASHTO Group Classifications. This raster attribute table was generated from the "Map Soil Properties and Interpretations" tool within the gSSURGO Mapping Toolset in the Soil Data Management Toolbox for ArcGIS™ User Guide Version 4.0 (https://www.nrcs.usda.gov/wps/PA_NRCSConsumption/download?cid=nrcseprd362255&ext=pdf) from GSSURGO that used their Map Unit Raster as the input feature (https://gdg.sc.egov.usda.gov/). The FY2018 Gridded SSURGO Map Unit Raster was created for use in national, regional, and state-wide resource planning and analysis of soils data. These data were created with guidance from the USDA NRCS. The fields named "*COMPPCT_R" can exceed 100% for some map units. The NRCS personnel are aware of and working on fixing this issue. Take caution when interpreting these areas, as they are the result of some data duplication in the master gSSURGO database. The data are considered valuable and required for timely science needs, and thus are released with this known error. The USDA NRCS are developing a data release which will replace this item when it is available. For the most up to date ssurgo releases that do not include the custom fields as this release does, see https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/home/?cid=nrcs142p2_053628#tools For additional definitions, see https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053627.

Massachusetts Top 20 Soils Data Layer

In an effort to provide a simple, statewide soils data layer, the Massachusetts Top 20 soils data layer is a statewide shapefile of the soil survey data that contains a single set of attributes for each soil survey map unit. The attributes provided are those soil properties or ratings that are most requested by soil survey users through the Web Soil Survey platform.

To create the shapefile, statewide gSSURGO data was downloaded from USDA’s Geospatial Data Gateway. A Soil Data Access query was used to extract certain data elements for these most-commonly requested soil properties and interpretations and exported into an excel file. This excel file was joined with the spatial data using the mukey and the resulting shapefile was exported. Descriptions for each attribute included in the shapefile is listed below.

For more information contact your local NRCS office or visit https://www.nrcs.usda.gov/wps/portal/nrcs/main/ma/soils/

Attribute

Attribute Name

Attribute description

Area Symbol

AREASYMBOL

Soil Survey Area Symbol

Map Unit Symbol

MUSYM

The symbol used to uniquely identify the soil mapunit in the soil survey.

Map Unit Key

MUKEY

The symbol used to uniquely identify the soil mapunit in the national soils information system database.

Area Name

AREANAME

Soil Survey Area name

Map Unit Name

MUNAME

Soil map unit name

Component Name

COMPNAME

Name of the dominant component of the soil map unit

Map Unit Kind

MUKIND

The kind of mapunit

Farmland Classification

FRMLNDCLS

Identification of map units as prime farmland, farmland of statewide importance, or farmland of unique importance.

Hydric Rating by Map Unit

HYDRCRATNG

Hydric soils are defined by the National Technical Committee for Hydric Soils (NTCHS) as soils that formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part (Federal Register, 1994). Under natural conditions, these soils are either saturated or inundated long enough during the growing season to support the growth and reproduction of hydrophytic vegetation. Reported for the dominant component of the map unit.

Drainage Class

DRAINCLASS

The natural drainage condition of the soil refers to the frequency and duration of wet periods. This column displays the dominant drainage class for the map unit, based on composition percentage of each map unit component.

Mineral Surface texture

MINSURFTEXT

The soil texture description of the first mineral soil horizon. Reported for the dominant component of the map unit.

T Factor

TFACTOR

Soil loss tolerance factor. The maximum amount of erosion at which the quality of a soil as a medium for plant growth can be maintained. Reported for the dominant component of the map unit.

Available Water Storage 0-100 cm

AWS100

Available water storage (AWS). The volume of water that the soil, to a depth of 100 centimeters, can store that is available to plants. It is reported as the weighted average of all components in the map unit and is expressed as centimeters of water. AWS is calculated from AWC (available water capacity) which is commonly estimated as the difference between the water contents at 1/10 or 1/3 bar (field capacity) and 15 bars (permanent wilting point) tension and adjusted for salinity and fragments.

Available Water Storage 0-25 cm

AWS25

Available water storage (AWS). The volume of water that the soil, to a depth of 25 centimeters, can store that is available to plants. It is reported as the weighted average of all components in the map unit and is expressed as centimeters of water. AWS is calculated from AWC (available water capacity) which is commonly estimated as the difference between the water contents at 1/10 or 1/3 bar (field capacity) and 15 bars (permanent wilting point) tension and adjusted for salinity and fragments.

Depth to Water Table

DEP2WATTBL

The shallowest depth to a wet soil layer (water table) at any time during the year expressed as centimeters from the soil surface, for components whose composition in the map unit is equal to or exceeds 15%. *These values are derived from the national database. They are intended for general planning purposes only and are not, in any way, intended to replace or supersede an on-site investigation. On-site investigations by certified soil evaluators are required by MA Environmental Code Title V for siting septic systems.

Dwellings with Basements

DWELLWB

The rating of the map unit as a site for dwellings with basements, expressed as the dominant rating class for the map unit, based on composition percentage of each map unit component.

Hydrologic Soil Group

HYDROLGRP

Hydrologic Group is a grouping of soils that have similar runoff potential under similar storm and cover conditions. This column displays the dominant hydrologic group for the map unit, based on composition percentage of each map unit component.

Nonirrigated Land Capability Class

NIRRLCC

This column displays the dominant capability class and subclass, under non-irrigated conditions, for the map unit based on composition percentage of all components in the map unit.

Local Roads and Streets

ROADS

The rating of the map unit as a site for local roads and streets, expressed as the dominant rating class for the map unit, based on composition percentage of each map unit component.

Septic Tank Absorption Fields

SEPTANKAF

The rating of the map unit as a site for septic tank absorption fields, expressed as the dominant rating class for the map unit, based on composition percentage of each map unit component. *These values are derived from the national database. They are intended for general planning purposes only and are not, in any way, intended to replace or supersede an on-site investigation. On-site investigations by certified soil evaluators are required by MA Environmental Code Title V for siting septic systems.

Representative Slope

SLOPE

The difference in elevation between two points, expressed as a percentage of the distance between those points. This column displays the slope gradient of the dominant component of the map unit based on composition percentage.

Flooding Frequency Class

FLOODING

The annual probability of a flood event expressed as a class. This column displays the dominant flood frequency class for the map unit, based on composition percentage of map unit components whose composition in the map unit is equal to or exceeds 15%.

Ponding Frequency Class

PONDING

The annual probability of a ponding event expressed as a class. This column displays the dominant ponding frequency class for the map unit, based on composition percentage of map unit components whose composition in the map unit is equal to or exceeds 15%

Corrosion of Concrete

CORCONCRET

"Risk of corrosion" pertains to potential soil-induced electrochemical or chemical action that corrodes or weakens concrete. The rate of corrosion of concrete is based mainly on the sulfate and sodium content, texture, moisture content, and acidity of the soil. Special site examination and design may be needed if the combination of factors results in a severe hazard of corrosion. The concrete in installations that intersect soil boundaries or soil layers is more susceptible to corrosion than the concrete in installations that are entirely within one kind of soil or within one soil layer. The risk of corrosion is expressed as "low," "moderate," or "high." Reported for the dominant component of the map unit.

Soil Taxonomy Classification

TAXCLNAME

A concatenation of the Soil Taxonomy subgroup and family for a soil (long name). Reported for the dominant component of the map unit.

Depth to Any Soil Restrictive Layer

CM2RESLYR

The distance in centimeters from the soil surface to the upper boundary of any restrictive layer. Reported for the dominant component of the map unit.

Restriction Kind

RESKIND

Type of nearly continuous layer that has one or more physical, chemical, or thermal properties that significantly reduce the movement of water and air through the soil or that otherwise provides an unfavorable root environment. Reported for the dominant component of the map unit.

Parent Material Name

PARMATNM

Reports the name for each of the parent materials that may occur in a vertical cross section of a soil. Reported for the dominant component of the map unit.

Unified Soil Classification (Surface)

UNIFSOILCL

Reports the Unified soil classification group symbol for the first mineral horizon of the dominant component of the map unit.

AASHTO Group Classification (Surface)

AASHTO

Reports the American Association of State Highway and Transportation Officials (AASHTO) class rating for the first mineral horizon of the dominant component of the map unit.

K Factor, Rock Free

KFACTRF

An erodibility factor which quantifies the susceptibility of soil particles to detachment by water. Reported for the first

From gridded National Soil Survey Geographic Database (gNATSGO). Used Soil Data Development Toolbox > gSSURGO Mapping Toolset > Create Soil Map Tool, Exported Data Layer to TIFF, and Used Spatial Analyst > Reclass > Lookup Tool to create this data layer and display the HYDROLGRP_. Follow instructions in "How to Create an On-Demand Soil Property or Interpretation Grid from gNATSGO". Shows sSSURGO data for California. A - sand, loamy sand, sandy loam B - loam, silt, loam or silt C - sandy clay loam D - clay loam, silty clay loam, sandy clay, silty clay, or clay The gridded National Soil Survey Geographic Database (gNATSGO) is a USDA-NRCS Soil & Plant Science Division (SPSD) composite database that provides complete coverage of the best available soils information for all areas of the United States and Island Territories. It was created by combining data from the Soil Survey Geographic Database (SSURGO), State Soil Geographic Database (STATSGO2), and Raster Soil Survey Databases (RSS) into a single seamless ESRI file geodatabase. The state-wide gNATSGO databases contain a 10-meter raster of the soil map units and 70 related tables of soil properties and interpretations. It is designed to work with the SPSD gSSURGO ArcTools. Users can create full coverage thematic maps and grids of soil properties and interpretations for large geographic areas, such as the extent of a State or the conterminous United States. Please note that for the CONUS database, only a 30 meter raster is included. SSURGO is the SPSD flagship soils database that has over 100 years of field-validated detailed soil mapping data. SSURGO contains soils information for more than 90 percent of the United States and island territories, but unmapped land remains. Click here for the current completion status of SSURGO mapping. STATSGO2 is a general soil map that has soils data for all of the United States and island territories, but the data is not as detailed as the SSURGO data. The Raster Soil Surveys (RSSs) are the next generation soil survey databases developed using advanced digital soil mapping methods. https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcseprd1464625) Use the Create A Soil Map ArcTool from the gSSURGO Mapping Toolset in the Soil Data Development Toolbox to make a TIFF data layer (Instructions: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcseprd1464625#grid). Make a Hydrological Soils Group Map, and display it using the Hydrolgrp_ attribute. NotesThe SPSD refreshes all published soil databases annually. gNATSGO will be included in the refresh cycle, which will provide a new up-to-date version of the database each year. gNATSGO is an ESRI file geodatabase. The soil map units are delivered only as a 10-meter raster version and are uniquely identified by the mukey, which is included in the attribute table. No vectorized version of the soil map units is included in gNATSGO. The database has 70 tables that contain soil attributes, and relationship classes are built into the database to define relationships among tables. The raster can be joined to the Mapunit and Muaggatt tables in the MUKEY field. The database contains a feature class called SAPOLYGON. The “source” field in this feature class indicates whether the data was derived from SSURGO, STATSGO2, or an RSS. A gNATSGO database was created for the conterminous United States and for each state or island territory that does not have complete coverage in SSURGO or has a published RSS. If you encounter an ArcMap error when working with a gNATSGO dataset that reads “The number of unique values exceeds the limit” try increasing the maximum number of unique values to render in your Raster ArcMap Options. Specific instructions can be obtained here: https://support.esri.com/en/technical-article/000010117

This dataset consists of a 100 meter resolution raster of depth and area weighted averages for soil pH for each map unit key (MUKEY) in the U.S. Department of Agriculture, Natural Resources Conservation Service's (NRCS) State Soil Geographical (STATSGO2) database (NRCS, 2016). This raster was developed from selected criteria of soil parameters from the STATSGO2 database and mapped to MUKEYs.