FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION
TITLE: MAJOR LAND RESOURCE AREAS
Geodataset Name: MLRA Geodataset Type: SHAPE Geodataset Feature: POLYGON
GENERAL DESCRIPTION:
This dataset contains Land Resource Regions (LRRs) and Major Land Resource Areas (MLRAs), originally established by the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS).
DATA SOURCE(S): United States Department of Agricultural
Natural Resources Conservation Service
SCALE OF ORIGINAL SOURCE MAPS: 1:2,000,000
DATE OF AUTOMATION OR SOURCE: 2002
GEODATASET EXTENT: State of Florida
Datafile Name: MLRA.DBF ITEM NAME WIDTH TYPE PRECISION SHAPE 8 SHAPEPOLY 0 AREA 9 DECIMAL 3 PERIMETER 9 DECIMAL 3 LRR_CODE 2 CHARACTER 0 MLRA_CODE 5 CHARACTER 0 LRR 55 CHARACTER 0 MLRA 55 CHARACTER 0 ACRES 16 DECIMAL 3 DESCRIPT 55 CHARACTER 0
FEATURE ATTRIBUTE TABLES CODES AND VALUES:
ITEM ITEM DESCRIPTION
SHAPE Data attribute inherent to the ESRI shapefile format,
which defines the data as a point, polyline, or polygon.
AREA Area of the polygon in square meters
PERIMETER Perimeter of polygon in coverage units
LRR_CODE Land Resource Region Code, descriptive name stored in LRR item
MLRA_CODE Major Land Resource Area Code, desciptive name stored in MLRA item
LRR Name of Land Resource Region, from Agriculture Handbook 296
MLRA Name of Major Land Resource Area, from Agriculture Handbook 296
ACRES Acres of Polygon
DESCRIPT FGDL added item based on MLRA
USER NOTES:
This is a polygon shapefile of the Land Resource Regions and Major
Land Resource Areas of the conterminous United States. Land
resource regions are geographic areas that are characterized by a
particular pattern of soils, climate, water resources and land uses.
(USDA, Soil Conservation Service, 1981). Major land resource
areas are subregions of the land resource regions and comprise
smaller homogeneous areas. The scale of this shapefile is
1:2,000,000. The primary use of this shapefile is for regional and
national display rather than specific local data analysis due to the
small scale (1:2,000,000) of this shapefile.
MLRA boundaries were revised in the mid-1990s from earlier versions
established in the 1970s and 1980s by the U.S. Department of Agriculture
(USDA) Natural Resources Conservation Service (NRCS), formerly the Soil
Conservation Service (SCS). The revised MLRA boundary coverage was
digitized at the Soil Survey Center in Lincoln, Nebraska, the most recent
version of which was completed in January of 1997. Buffer polygons were
added to the U.S. national boundaries and shoreline by NRCS National
Cartography and Geospatial Center in Fort Worth, Texas, for use with NRCS
National Resources Inventory (NRI) digitizedsample sites. These buffered
boundaries were later removed by the NRCS National Headquarters office,
Resource Assessment Division (RAD) in May 2000, and the national shoreline
and outer boundaries were made to conform to standard boundaries established
for State of the Land series maps (http://www.nhq.nrcs.usda.gov/land). Those
standard U.S. national boundaries and shoreline are based on 1:2,000,000 scale
8-digit hydrologic unit coverage obtained from the U.S. Geological Survey, circa
1990, and were edited by the National Center for Resource Innovations (NCRI) in
Washington, DC, and subsequently by NRCS/NHQ/RAD.
A note concerning data scale:
Scale is an important factor in data usage. Certain scale datasets are not
suitable for some project, analysis, or modelling purposes. Please be sure
you are using the best available data.
1:24000 scale datasets are recommended for projects that are at the county
level. 1:24000 data should NOT be used for high accuracy base mapping such
as property parcel boundaries.
1:100000 scale datasets are recommended for projects that are at the
multi-county or regional level.
1:250000 scale datasets are recommended for projects that are at the
regional or state level or larger.
Vector datasets with no defined scale or accuracy should be considered
suspect. Make sure you are familiar with your data before using it for
projects or analyses. Every effort has been made to supply the user with
data documentation. For additional information, see the References section
and the Data Source Contact section of this documentation. For more
information regarding scale and accuracy, see our web pages at:
http://www.geoplan.ufl.edu/education.html
FGDL QUALITY ASSURANCE STATUS:
-Projected data to FGDL Albers HPGN (See "Map Projection Parameters" below). -Clipped to the State of Florida -DESCRIPT item added based on MLRA -Upcased all character records. -Dropped internal coverage items: Mlra_cov_, Mlra_cov_i -Updated Area and Perimeter
REFERENCES:
NRCS National Headquarters, Resource Assessment Division (RAD). See USDA Agriculture Handbook 296 "Land Resource Regions and Major Resource Areas of the United States" for a look at an earlier version of the map and an explanation of MLRA and LRR designations.
DATA LINEAGE SUMMARY:
GeoPlan downloaded this dataset in shapefile format from the USDA/NRCS ftp site. (ftp.nhq.nrcs.usda.gov/pub/outgoing/land/arc_export/us48mlra.e00.zip). When received, the data was in the following projection: Albers, Datum: NAD 27, Spheroid: Clarke 1866, Units: Meters. The shapefile was clipped to the State of Florida boundary and projected to FGDL Albers HPGN (See "Map Projection Parameters" below). The DESCRIPT item was added based on the MLRA item, all character items were upcased, internal coverage items were removed, and Area and Perimeter were updated.
MAP PROJECTION PARAMETERS:
Projection ALBERS Units METERS Datum HPGN Spheroid GRS1980 1st standard parallel 24 0 0.000 2nd standard parallel 31 30 0.000 Central meridian -84 0 0.000 Latitude of projection's origin 24 0 0.000 False easting (meters) 400000.00000 False northing (meters) 0.00000
DATA SOURCES CONTACT(S):
Name: United States Department of Agricultural/
Natural Resources Conservation Service
Abbr.name: USDA/NRCS
Address: Natural Resources Conservation Service
Attn: Conservation Communications Staff
P.O. Box 2890
Washington, DC 20013
Web site: http://www.nrcs.usda.gov/
Contact Person: Dean Oman
FGDL CONTACT:
Name: Florida Geographic Data Library
Abbr. Name: FGDL
Address: Florida Geographic Data Library
431 Architecture
PO Box 115706
Gainesville, FL 32611-5706
Web site: http://www.fgdl.org
Contact FGDL:
Technical Support: http://www.fgdl.org/fgdlfeed.html
FGDL Frequently Asked Questions: http://www.fgdl.org/fgdlfaq.html
FGDL Mailing Lists: http://www.fgdl.org/fgdl-l.html
For FGDL Software: http://www.fgdl.org/software.html