Description: This data set consists of general soil association units. It was
developed by the National Cooperative Soil Survey and supersedes
the State Soil Geographic (STATSGO) data set published in 2006.
It consists of a broad based inventory of soils and nonsoil areas
that occur in a repeatable pattern on the landscape and that can
be cartographically shown at the scale mapped. The data set was
created by generalizing more detailed soil survey maps. Where more
detailed soil survey maps were not available, data on geology,
topography, vegetation, and climate were assembled, together with
Land Remote Sensing Satellite (LANDSAT) images. Soils of like areas
were studied, and the probable classification and extent of the soils
were determined.
Map unit composition was determined by transecting or sampling areas
on the more detailed maps and expanding the data statistically to
characterize the whole map unit.
This data set consists of georeferenced vector digital data and
tabular digital data. The map data were collected in 1-by 2-degree
topographic quadrangle units and merged into a seamless national
data set. It is distributed in state/territory and national extents.
The soil map units are linked to attributes in the National Soil
Information System data base which gives the proportionate extent of
the component soils and their properties.