USDA-NASS Cropland Data Layer: Illinois 1999-2006
The United States Department of Agriculture, National Agricultural Statistics Service (USDA-NASS) Cropland Data Layer (CDL) for Illinois is a raster, geo-referenced, categorized land cover data layer. Between 1999-2005 this data layer was produced annually using satellite imagery from the Thematic Mapper (TM) instrument on Landsat 5 and the Enhanced Thematic Mapper (ETM+) on Landsat 7. The ground resolution is 30 meters by 30 meters. Beginning in 2006, the CDL data layer uses the satellite imagery from the Indian Remote Sensing RESOURCESAT-1 Advanced Wide Field Sensor (AWiFS), which has a ground resolution of 56 x 56 meters. The Illinois Cropland Data Layer is aggregated to 13 standardized categories for display purposes with the emphasis being agricultural land cover. No individual farmer's reported data is included or derivable from the Cropland Data Layer.
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The NASS Cropland Data Layer for Illinois is part of a series in which several states are categorized annually based on the extensive field observations collected during the annual NASS June Agricultural Survey. This is a national survey based on a stratified random sample of land areas selected from each state's area frame. An area frame is a land use stratification based on percent cultivation. Our field enumerators are given questionnaires to ask farmers what, where, when and how much they are planting. Our surveys focus on cropland, but the enumerators record all land covers within the sampled area of land whether it is cropland or not. NASS uses broad land use categories to define land that is not under cultivation, including; non-agricultural, pasture/rangeland, waste, woods, and farmstead.
Download NASS data for Illinois
| 1999 GRID
1999 IMG |
2000 GRID
2000 IMG |
2001 GRID
2001 IMG |
2002 GRID
2002 IMG |
2003 GRID
2003 IMG |
2004 GRID
2004 IMG |
2005 GRID
2005 IMG |
| 2006 CDL (175Mb) Changes in the 2006 attribute domain values and definitions are detailed in the metadata. |
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Purpose
The purpose of the Illinois Cropland Data Layer Program is to use satellite imagery on an annual basis to provide supplemental acreage estimates for the state's major commodities ,and to produce digital, crop specific, categorized geo-referenced output products. These data are intended for geographic display and analysis at the state level. The cropland data layers are provided "as is". USDA-NASS does not warrant results you may obtain using the data.
Copyright Restrictions
There are NO copyright restrictions with the NASS Cropland Data Layer imagery. The categorized imagery is considered public domain and free to redistribute. However, NASS would appreciate acknowledgment or credit for the usage of our categorized imagery.
Attributes
The following is a cross-reference list of the categorization codes and land covers used in all states involved in the Cropland Data Layer Program. Not all land cover categories listed below will appear in an individual state; the Illinois Cropland Data Layer uses 13 of these categories.
| Attribute Domain Values and Definitions ROW CROPS 1-20 |
|
|---|---|
| Categorization Code | Land Cover |
| 1 | Corn |
| 2 | Cotton |
| 3 | Rice |
| 4 | Sorghum |
| 5 | Soybeans |
| 6 | Sunflowers |
| 10 | Peanuts |
| 11 | Tobacco |
| Attribute Domain Values and Definitions SMALL GRAINS & HAY 21-40 |
|
| Categorization Code | Land Cover |
| 21 | Barley |
| 22 | Durum Wheat |
| 23 | Spring Wheat |
| 24 | Winter Wheat (AR,IL,MS,NM) |
| 25 | Other Small Grains & Hay (Oats, Millet, Rye & Winter Wheat, Alfalfa & Other Hay) |
| 26 | Winter Wheat/Soybeans Double Cropped |
| Attribute Domain Values and Definitions OTHER CROPS 41-60 |
|
| Categorization Code | Land Cover |
| 41 | Beets |
| 42 | Dry Edible Beans |
| 43 | Potatoes |
| 44 | Other Crops (Canola, Flaxseed, Safflower & very small acreage crops) |
| 50 | State 560 CRP |
| 51 | State 561 Popcorn |
| 52 | State 562 Snap Beans |
| 53 | State 563 Green Peas |
| 54 | State 564 Pumpkins |
| 55 | State 565 Apples |
| 56 | State 566 Peaches |
| 57 | State 567 Sweet Corn - fresh |
| 58 | State 568 Sweet Corn - processing |
| 59 | State 569 Other Crops |
| Attribute Domain Values and Definitions OTHER LAND 61-80 | |
| Categorization Code | Land Cover |
| 61 | Fallow/Idle Cropland |
| 62 | Pasture/Range/CRP/Non Ag (Permanent & Cropland Pasture, Waste & Farmstead) |
| 63 | Woods |
| Attribute Domain Values and Definitions OTHER 81-99 | |
| Categorization Code | Land Cover |
| 81 | Clouds |
| 82 | Urban |
| 83 | Water |
| 84 | Roads/Railroads |
| 85 | Ditches/Waterways |
| 86 | Buildings/Homes/Subdivisions |
| 87 | Wetlands |
| 88 | Grassland |
| 90 | Mixed Water/Crops |
| 91 | Mixed Water/Clouds |
Classification accuracy is generally between 85% to 95% correct for agricultural-related land cover categories. Detailed classification statistics are available on the official NASS Cropland Data Layer CD-ROM.
The categorized images are co-registered to ortho-rectified GeoCover Stock Mosaic images using automated block correlation techniques. The GeoCover Stock Mosaics are within 50 meters root mean squared error overall.