Delaware Strata Map

Metadata also available as -[Parseable Text]

Frequently-anticipated questions:

What does this data set describe?

Title: Delaware Strata Map

Abstract:

The United States Department of Agriculture (USDA), National Agricultural Statistics Service (NASS) area sampling frame is a delineation of all parcels of land for the purpose of later sampling the parcels. The area frame is constructed by visually interpreting satellite imagery to divide a state into homogenous land use areas (strata) based on percent cultivated. The strata are typically defined as low, medium or high percent cultivated, non-agricultural land, urban use, agri-urban, or water. The boundaries of the strata usually follow identifiable features such as roads, railroads and waterways. The strata boundaries do not coincide with any political boundaries, with the exception of state boundaries.

Supplemental_Information: N/A

  1. How should this data set be cited?

United States Department of Agr, National Agricultural Statistics Service, 1996, Delaware Strata Map: U.S. Department of Agriculture, National Agricultural Statistics Service, Fairfax, Virginia.

Online Links:

o        <http://www.nass.usda.gov/research>

2.      What geographic area does the data set cover?

West_Bounding_Coordinate: -79.29

East_Bounding_Coordinate: -75.02

North_Bounding_Coordinate: 39.43

South_Bounding_Coordinate: 37.54

3.      Does the data set describe conditions during a particular time period?

Calendar_Date: 2002

Currentness_Reference:

1997: Publication date of strata boundaries. 1996: Creation of original area sampling frame strata boundaries.

4.      How does the data set represent geographic features?

a.    How are geographic features stored in the data set?

Indirect_Spatial_Reference:

U.S. Department of Commerce, 1990, Counties and Equivalent Entities of The United States, Its Possessions, and Associated Areas (Federal Information Processing Standard 6-4): Washington, D.C. National Institute of Standards and Technology.

This is a Vector data set. It contains the following vector data types (SDTS terminology):

b.    What coordinate system is used to represent geographic features?

Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000278. Longitudes are given to the nearest 0.000278. Latitude and longitude values are specified in Decimal Degrees.

1.      How does the data set describe geographic features?

Land Use Strata

Homogeneous land use area based on percent cultivated (Source: U.S. Department of Agriculture, National Agricultural Statistics Service)

Strata

Land use category based on percent cultivated (Source: U.S. Department of Agriculture, National Agricultural Statistics Service)

 

Value

Definition

13

50% cultivated, (cultivated categories consist of land used for

crops, the remaining portion of land in the cultivated strata may include pasture, woods, waste, rangeland, etc.)

20

15%-50% cultivated, (cultivated categories consist of land used for crops, the remaining portion of land in the cultivated strata may include pasture, woods, waste, rangeland, etc.)

31

Agri-urban with > 100 homes per square mile (less than 15% cultivated)

32

Commercial/dense urban with > 100 homes per square mile (city center with 0% cultivated)

40

< 15% cultivated, (cultivated categories consist of land used for crops, the remaining portion of land in the cultivated strata may include pasture, woods, waste, rangeland, etc.)

50

Non-agricultural (state or national parks, military bases, etc.)

62

Water

 

Sum_area

The stratum area in square miles. (Source: U.S. Department of Agriculture, National Agricultural Statistics Service)

Range of values

Minimum:

5.2 (actual value, not range)

Maximum:

957.683 (actual value, not range)

 

Sum_acres

The number of acres in a stratum. (Source: U.S. Department of Agriculture, National Agricultural Statistics Service)

Range of values

Minimum:

3328.0 (actual value, not range)

Maximum:

612917.12 (actual value, not range)

 

Entity_and_Attribute_Overview:

To retain consistency in symbology with data viewed with ArcView mapping software, the .avl file associated with the black and white strata map requires strata symbol modification for use with ArcGIS. The symbols needing modification are described as Agri-Urban > 100 Homes per sq. Mi. and Non Agriculture. Both symbols use ESRI's 10% simple hatch: outline width: 0.01, offset: 220, separation 1.0 and line width: 0.2. The Agri-Urban line hatch is displayed at 90 degrees and Non-Agriculture displayed at 0 degrees.

Entity_and_Attribute_Detail_Citation: N/A

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

2.      Who also contributed to the data set?

Area Frame Section staff

3.      To whom should users address questions about the data?

Area Frame Section staff
USDA/NASS/RDD/AFS
3251 Old Lee Highway, Suite 301
Fairfax, VA 22030

703-235-1971 (voice)
HQ_RD_OD@nass.usda.gov

Why was the data set created?

These data are intended for geographic display and analysis at the state level. The data should be displayed and analyzed at a scale of 1:100,000 or smaller (e.g., 1:250,000, etc.). The strata data are provided "as is". USDA/NASS does not warrant results you may obtain using the strata data.

How was the data set created?

  1. From what previous works were the data drawn?

TMimagery (source 1 of 6)

Earth Observation Satellite Company, 1995, Landsat 5 Thematic Mapper imagery: Earth Observation Satellite Company, Lanham, Maryland.

Type_of_Source_Media: CD-ROM

Source_Contribution: spatial and attribute information

US GeoData (source 2 of 6)

U.S. Geological Survey (USGS), 1989, US DLG vector files: U.S. Geological Survey (USGS), Reston, VA..

Type_of_Source_Media: CD-ROM

Source_Contribution: spatial and attribute information

SureMaps (source 3 of 6)

Horizons Technology, Inc., 1989, Mosaiced topographic raster: Horizons Technology, Inc., San Diago, CA.

Type_of_Source_Media: CD-ROM

Source_Scale_Denominator: 100,000

Source_Contribution: spatial and attribute information

SPOT (source 4 of 6)

Corporation, SPOT Image , 1995, SPOT Image: SPOT Image Corporation, Reston, VA..

Type_of_Source_Media: CD-ROM

Source_Contribution: spatial and attribute information

JES (source 5 of 6)

National Agricultural Statistics Service, 1995, June Enumerative Survey: National Agricultural Statistics Service, Fairfax, VA.

Type_of_Source_Media: Survey summary data

Source_Contribution: Attribute information

AFSpaper (source 6 of 6)

National Agricultural Statistics Service, 1987, Area Frame Design for Agricultural Surveys: NASS/USDA, Washington, DC.

Type_of_Source_Media: paper

Source_Contribution: attribute information

  1. How were the data generated, processed, and modified?

Date: 1991 (process 1 of 1)

The area sampling frame for Delaware was constructed in 1996 for use in 1997 and was based on mosaiced 1:100,000 scale topographic raster data, U.S. Department Of Interior US GeoData, 30-meter pixel resolution Landsat 5 Thematic Mapper imagery and 20 meter pixel resolution SPOT Imagery. Individual county files were merged into a single state file. The coordinates for the strata polygons are unprojected to geographic latitude and longitude (decimal degrees). The spatial data file format is Environmental Systems Research Institute's ArcView shapefile format.

Data sources used in this process:

How reliable are the data; what problems remain in the data set?

1.      How accurate are the geographic locations?

The sources used for digitizing strata boundaries are 1:100,000 scale topographic raster data

2.      Where are the gaps in the data? What is missing?

There are no known gaps or missing data. This data set includes the area in square miles and number of acres for each strata. Because the area sampling frame strata boundaries may not be coincident with strata boundaries of adjacent states.

3.      How consistent are the relationships among the observations, including topology?

No checks for topological consistency were performed on this data set.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None

Use_Constraints:

None. Acknowledgment of the U.S. Department of Agriculture, National Agricultural Statistics Service would be appreciated in products derived from these data.

  1. Who distributes the data set? (Distributor 1 of 1)

USDA/NASS/RDD/GIB/AFS
3251 Old Lee Highway, Suite 301
Fairfax, VA 22030

703-235-1971 (voice)

Contact_Instructions: N/A

  1. What's the catalog number I need to order this data set?

Downloadable Data

3.      What legal disclaimers am I supposed to read?

Users of the strata data are solely responsible for interpretations made from the product. The strata data are provided "as is". USDA/NASS does not warrant results you may obtain by using the strata data. Feel free to contact our staff at (HQ_RD_OD@nass.usda.gov) if technical questions arise in the use of the strata data.

4.      How can I download or order the data?

Data format:

ESRI Shapefile

Network links:

<http://www.nass.usda.gov/research>

o        Cost to order the data: There is no charge for the online option.

o        Special instructions:

N/A

Who wrote the metadata?

Dates:

Last modified: 06-Aug-2002

Metadata author:

Thomas Lloyd
USDA/NASS/RDD/GIB/AFS
3251 Old Lee Highway, Suite 301
Fairfax, VA 22030

703-235-1971 (voice)
HQ_RD_OD@nass.usda.gov

Metadata standard:

FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.7.10 on Thu Dec 19 08:56:37 2002