County Level Soil Surveys in Digital Format — SSURGO
Summary - what is SSURGO?
Vermont SSURGO (Soil Survey Geographic Database) information includes the digital soil maps and the accompanying soil properties and interpretations database. This data is primarily used in GIS applications.
The SSURGO user should be knowledgeable of the structure of the soil database and familiar with GIS technology.
There are three levels of digital soils data:
- SSURGO - is the most detailed county level data
- STATSGO - is less detailed state-wide map
- NATSGO - is a very general soil map of the entire U.S.
The majority of counties in Vermont use 1:20,000 mapping scale for SSURGO data. The minimum area mapped is, in general, about 3 acres. This level of mapping is designed for use by farmers, landowners, watershed groups, towns, and county/regional/state natural resource planning agencies. The data is available for download from the sites listed below.
Two options for downloading SSURGO data:
- Vermont Center for Geographic Information (VCGI)
- USDA / NRCS
Vermont Center for Geographic Information - State GIS Warehouse
on this site choose the VGIS Data Warehouse Tab then pick the Theme - Geologic and Geophysical - search for the keyword Soils
* Of especial note, is the so-called "Top Twenty Table" included in the SSURGO attribute data. This is a condensed and easy to use single table, containing the most frequently used data attributes. On the VCGI site it can be found in VGIS Data Warehouse / Products / Data Bundles.
Datamart - is no longer available - use Web Soil Survey instead - look for the "Download Soils Data" Tab
This data is available at 1:24,000 scale. In Vermont the data were developed with the intended publication scale of 1:20,000. A "scale waiver" was permitted for many Vermont counties, to allow this non-standard scale and make soil data compatible across Vermont.
A complete SSURGO data set consists of:
- map data (as ArcView shape files)
- attribute data (dbf files - a multitude of separate tables)
- database template (MS Access format - this helps with understanding the structure and linkages of the various tables)