Cropland Data Layer (CDL) are satellite
images depicting agricultural land cover. The images 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.
Iowa county CDL maps are available through the links below.
The entire inventory of CDL products, including metadata and
accuracy assessments, is available online at http://nassgeodata.gmu.edu/CropScape/ .