ERS GIS Map Services and API User Guide
All of the ERS mapping applications, such as the Food Environment Atlas and the Food Access Research Atlas, use map services developed and hosted by ERS as the source for their map content. These map services are open and freely available for use outside of the ERS map applications. Developers can include ERS maps in applications through the use of the map service REST API, and desktop GIS users can use the maps by connecting to the map server directly.
General Map Service Documentation
Over 30 ERS map services have been created, each containing anywhere from 4 to 70 map layers. The majority of the services consist of national maps displaying data at the county-level. The Food Access Research Atlas service is Census-tract based. A good way to discover and browse the available services and maps is to use the ERS map applications themselves. The Food Environment Atlas, The Atlas of Rural and Small-Town America, The Farm Program Atlas, and the SNAP Data System all use a similar data organization scheme of “Categories” and “Maps.” Each category in the application corresponds to a map service; each map is a layer in that map service. The Food Access Research Atlas is the exception to this scheme as it uses only a single ERS map service, plus an ESRI-hosted background map.
The ARC GIS REST Services Directory lists all available map services.
Summary of ERS map services and where they are used:
NASS 2012 Ag Census Map Services
In partnership with NASS, ERS developed the 2012 Ag Census Maps application, and is also hosting the map services for that application. Documentation for those map services is here.
Desktop User Instructions
To use the ERS map services in a desktop application, such as ArcMap or ArcGIS Online:
- Browse the service description and REST directory to determine which services and maps meet your needs, and
- Follow the instructions here to add the maps to your document. Use ‘gis.ers.usda.gov’ as the server specification.
Developer API Instructions
The services can be accessed through ArcGIS Server REST API. JSON and SOAP interfaces are also available. See the detailed documentation, including general usage instructions, service properties, and methods.