National Resource Inventory (NRI)

Illinois July 2007 State Report

Estimates presented here are based upon the latest information from the National Resources Inventory (NRI). The NRI is a longitudinal sample survey based upon scientific statistical principles and procedures. It is conducted by the U.S. Department of Agriculture's Natural Resources Conservation Service (NRCS), in cooperation with Iowa State University's Center for Survey Statistics and Methodology. These results are based upon the 2003 Annual NRI, which statistically updates 1997 NRI results with data collected during 2000 - 2003. The NRI was conducted on a five-year cycle during the period 1982 to 1997, but now is conducted annually. NRI data were collected every five years for 800,000 sample sites (8,397 sample sites in Illinois); annual NRI data collection occurs at slightly less than 25 percent of these same sample sites.

NRI data release procedures are affected by implementation of an annual data collection approach, because the scale of NRI estimates is affected by these reduced sample sizes. Estimates are being released when they meet NRI statistical standards and are scientifically credible in accordance with NRCS policy, and in accordance with OMB and USDA Quality of Information Guidelines.

The 2003 Annual NRI data are suitable for national, many regional, and some state level analyses. Selected state-level results are reported here. These results will be supplemented in early to mid 2008 with additional estimates that compare net change and land cover/use dynamics with previous inventories.

Until these supplements are released, direct comparisons between 1997 and 2003 NRI estimates to determine change or trends will produce incorrect inferences and is scientifically invalid.
 

2003 Key Findings