Soil Survey Geographic Database
National Cooperative Soil Survey and USDA Natural Resources Conservation Service
Data Specifications
- Area of Coverage: Available for most counties and areas throughout the U.S. and its territories.
- Date(s) Available: Field mapping began in 1950's and continues today. The associated digitizing effort began in early 1990's.
- Format: ESRI Shapefile, ArcInfo coverage, and ArcInfo Interchange file formats. Attribute data are distributed in ASCII format and can be imported into a Microsoft Access database. Metadata are in ASCII and XML format.
- Scale: Predominately 1:12,000 or 1:24,000, with some scales ranging to 1:63,360.
- Minimal Mapping Unit: Range from one to ten acres
- Accuracy: The mapping bases meet national map accuracy standards
Overview
Sample of SSURGO data in the Web soil survey for Madeline Island, Apostle Islands National Seashore, WI
The Soil Survey Geographic (SSURGO) database depicts information about the kinds of soils and distribution of soils on the landscape. This data set is a digital soil survey and generally is the most detailed level of soil geographic data available. It consists of a georeferenced digital map data, computerized tabular attribute data, and associated metadata. The tabular component defines soil characteristics, properties, and potential limitations or suitability for various uses. It is typically imported into a database for querying, reporting, and analysis. The spatial component consists of soil polygons, lines and points that are typically viewed and analyzed using a geographic information system (GIS).