The National Resources Inventory (NRI) is a scientifically-designed, longitudinal panel survey of the Nation's soil, water, and related resources designed to assess conditions and trends every five years. The NRI is conducted by the Natural Resources Conservation Service (NRCS), an agency of the U.S. Department of Agriculture (USDA), in cooperation with the Iowa State University (ISU) Statistical Laboratory. The NRI was originally designed (in 1982) to obtain natural resource data usable for analysis at a sub-State (multi-county) level. Of interest were estimates that could be developed for such sub-State entities as Major Land Resource Areas (MLRA), Soil Conservation Service Administrative Areas, 4-digit Hydrologic Unit Areas (HUA), and Water Resources Council aggregated sub-areas (ASA). The sample was selected giving particular attention to MLRA portions of States. Exact locations of NRI sampling points are not publicly available, but they are identified according to presence in a county, MLRA, and hydrologic unit area. This data layer combines those three data sets, as well as Federal Lands, to produce spatial representation for NRI results.
The NRI Polygon Boundaries data set was compiled in order to simplify pesticide risk assesment and to provide a common data set upon which to perform analysis for all stakeholders.
This data set follows similiarly to the 1997 (revised December 2000) National Resources Inventory data set produced by the U.S. Department of Agriculture, Natural Resources Conservation Service.
publication date
Results derived from the NRI database are estimates. All NRI results have some degree of uncertainty associated with them. Interpretation of NRI results requires an understanding of the amount of this uncertainty associated with each estimate, as well as an understanding of the inventory procedures. Since the NRI employs recognized statistical methodology, it is possible to quantify this statistical uncertainty. NRI data were collected at more than 800,000 sample sites nationwide. This is a very large sample, which means that the data can be legitimately used to analyze issues at many geographic levels -- national, regional, State, and sub-State (multi-county). However, the NRI was not designed for analyzing issues at the county level.
897-B Harrison Street, S.E.
This data set is a compilation of four original source data sets, including the following: 1) Major Land Resources Areas of the United States (MLRA) - compiled National Atlas of the United States 2) County Boundaries - compiled by the National Atlas of the United States from 1:2,000,000 USGS DLGs 3) Hydrologic Unit Codes (HUCS8) - produced by the U.S. Geological Survey from 1:250K Hydrologic Unit Maps 4) Federal Lands - compiled by National Atlas of the United States.
Intersected the original source data sets: MLRA, HUCS8, CountyBoundaries, using ArcINFO workstation geoprocessing command, Intersect.
Dissolved original source Federal Lands polygon on FederLand attribute field, using ArcGIS geoprocessing tool, Dissolve.
Unioned the dissolved Federal Lands data set to the intersected HUCS8/MLRA/CountyBoundaries data set, using ArcMap geoprocessing tool, Union, resulting in the NRI polygon data set.
Created unique identification field, NRI_PolyID, within the attributes table of the newly compiled NRI polygon data set.
Created metadata
Aggregated data, using the ArcGeoprocessing Tool, DISSOLVE, based on the FIPSMLRAHUC and FederalLands fields, in order to reduce duplicate data.
Aggregate data based on the fields, NRI_POLY_ID and FIPSMLRAHUC, using the Geoprocessing Tool, DISSOLVE, in order to reduce duplicate data.
Dataset copied.
Length of feature in internal units.
ESRI
Area of feature in internal units squared.
ESRI
Internal feature number.
ESRI
Feature geometry.
ESRI
Federal Lands: Those land areas over 640 acres identified as being administered by the United States Federal Goverment.
National Atlas of the United States
Unique numeric Code for NRI reference
1500 Research Parkway, Suite B223
None
Data can be downloaded from www.geostac.org with a registered user ID and password provided by the Spatial Sciences Laboratory.
Not Applicable
897-B Harrison Street, S.E.