Cropland Area Monitoring Program At the National Agricultural Statistics Service.

For the past 16 years, the US Department of Agriculture/National Agricultural Statistics Service (NASS) produced an annual crop specific land cover product called the Cropland Data Layer (CDL), depicting more than 100 unique crop categories across the US. NASS derived this unique cropland area monitoring program via remote sensing using a supervised land cover classification approach. The national CDL product is available for years 2008 through 2012, with the entire dataset disseminated via the online CropScape (http://nassgeodata.gmu.edu/CropScape) portal.

During the growing season, NASS derives monthly cropland area estimates from the CDL, delivering robust statistical estimates using a regression approach for the major crops at the state, agricultural statistics district, and county levels. The CDL is a geospatial product with a pixel resolution of 30 meters or .22 acres, and is derived using a combination of on-the-ground farm information including field location, crop type, and ancillary datasets of elevation, tree canopy, and urban infrastructure and satellite data collected from medium resolution sensors such as Landsat and the Disaster Monitoring Constellation. The CDL has classification accuracies between 85 to 95 percent for the major crops and provides users the ability to quantify land cover change, calculate conversion of grassland/wetlands, crop rotations, environmental and biodiversity studies, and derive total cultivated area.

The CropScape portal was constructed to disseminate, visualize, query, and analyze the CDL through standard geospatial web services in a publicly accessible open online environment. CropScape currently serves the entire inventory of historical CDL products and provides mashup capabilities to other geospatial portals for data queries, providing a method for automatic area of interest data delivery and on-demand crop statistics for uses in other applications.