The SSURGO soils data are the most accurate and comprehensive federal soils products available. The levels of soils data include:
-SSURGO is the most detailed county-level data.
-STATSGO is less detailed statewide map.
-NATSGO is a very general soil map of the entire U.S.
The SSURGO level of soil mapping is designed for use by landowners, townships, and counties for natural resource planning and management and regional applications. It is appropriate for watershed planning and some agricultural uses. The user should be knowledgeable about soils data and their characteristics. This database is scheduled to be completed for the entire country in 2008. Approximately 85 percent of all counties in Virginia have digital SSURGO soils data available. The Soils section located in the supplemental METADATA file includes an illustration that shows SSURGO soil data (left) and SSURGO soils data made transparent and superimposed over aerial photography (right).
The SSURGO soil polygons associated with the Virginia County Data Series have been permanently joined with selected attributes. Not all attributes have been joined to the spatial data. These polygon files are disseminated as Shapefiles, and may be large in size (1 to 2 MB).
Data Type: Polygon
Data Format: Shapefile
-MUSYM(Map Unit Symbol): a symbol used to identify the soil map unit on the soil map.
-MUKEY: A symbol created by concatenation of the soil survey area symbol (ssaid) and map unit symbol (musym). It uniquely identifies a map unit within a state. For example, ssaid 061 and musym 1 are stored as muid 061001. The muid is used as a key for linking information in the MUIR tables.
-SYMBOL: same as MYSYM
-NAME: Soil name and general slope information.
-KIND: Code identifying the kind of map unit: Consociation; Association; Undifferentiated Group; Complex.
-TTLAcres: the total number of acres by MYSYM group
-Class: The Prime Farmland Classification of the map unit.
-HEL: The highly erodible lands rating for the soil map unit. The rating is based an evaluation of the wind erosion hazard of the components of the map unit. If all components are of a single class that class applies, if not then a 2 (Potential Highly Erodible) is assigned.
-HEL Water: The highly erodible lands rating for the soil map unit. The rating is based an evaluation of the water erosion hazard of the components of the map unit. If all components are of a single class that class applies, if not then a 2 (Potential Highly Erodible) is assigned.
-Zone: 17 or 18 (Contingent on locality, refer to UTM map in the Appendix)
-Spheroid: NAD 83
-Source: NRCS Geospatial data Gateway