February 16, 2010

USDA's National Agricultural Statistics Service (NASS) has released new satellite images depicting agricultural land cover across most of the nation for the 2009 crop year. The images, referred to as cropland data layers (CDL), are a useful tool for monitoring crop rotation patterns, land use changes, water resources and carbon emissions.

These crop-specific, digital data layers are suitable for use in geographic information systems (GIS) applications. They can be used by agribusinesses, farmers, government agencies, researchers and academic institutions to study pesticide risk, epidemiology, transportation, fertilizer usage, carbon dioxide flux and other topics.

NASS produced the CDLs using satellite images observed at 56-meter (0.775 acres per pixel) resolution and collected from the Resourcesat-1 Advanced Wide Field Sensor (AWiFS), Landsat Thematic Mapper and Moderate Resolution Imaging Spectroradiometer (MODIS). The collection of images was then categorized using on-the-ground farm information including field location, crop type, land cover, elevation, tree canopy and urban infrastructure.

For the first time, the CDL images are available for 47 of the 48 contiguous states. Data for the final state, Florida, will be available this spring pending the availability of certified farm data required to produce the images. NASS is also making available, for the first time, the New Mexico CDL for 2008.

The entire inventory of CDL products, including metadata and accuracy assessments, is available online at the USDA Natural Resources Conservation Service's Geospatial Data Gateway and at this NASS Web site.

USDA NASS News Release