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	GIS Data Table > Land Cover Training Data > Land Cover Training Sites (GAP) 2002-2004, Metadata

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nv_complete

Identification_Information:

Citation:

Citation_Information:

Originator: U.S. Environmental Protection Agency, ORD/NERL/LEB
Publication_Date: April 2005
Title: nv_complete
Geospatial_Data_Presentation_Form: vector digital data
Online_Linkage: N/A

Description:

Abstract:: Field Data Collection: An ideal dataset for landcover modeling has two critical characteristics: 1) it adequately samples the range of environmental settings in a landscape, and 2) it contains enough data to robustly model each plant community of the classification. To classify the vegetation of a five state region thus requires thousands of training sites. Because of the large volume of data required, only enough time is spent at each site to collect the minimum amount of ecological detail to confidently assign an alliance labels. Field crews select training sites opportunistically based on homogeneity of plant species composition, landform, and spectral characteristics. Three essential steps are performed at each site: plant community characterization, site delineation, and photographic documentation. Plant Community Characterization: Three basic types of information that are collected for each training site: 1) ocular estimates of vegetative cover subdivided into growth form (e.g., tree, shrub, forb/graminoid) and plant species, 2) visual estimates of abiotic ground cover (e.g., rock fragments, bedrock, water), and 3) measurements and classification of the communities' landscape setting (e.g., landform, topographic attributes). Site Delineation: With the assistance of a laptop computer, a polygon delineating the training site is hand-digitized in the field. To assist in this task, field crews utilize satellite imagery, digital elevation models (DEMs), and digital raster graphs (DRGs) as guides. Field polygons are a minimum of 90x90 meter areas in most cases though some communities of special concern (e.g., riparian areas) are delineated with smaller dimensions. Photographic Documentation: To document each training site, a digital photograph is collected as a reference should any questions arise regarding it alliance, ecological system or NLCD label. To construct a vegetation map of Nevada with 50+ plant communities, we need hundreds of examples, or training sites, of each community that represent their distribution across ecological and spectral gradients. We have 6 months to collect 10,000+ training sites distributed across 60% of Nevada. Because we need to collect a large amount of data in a short time, we must use our field time efficiently. Our field methodology is designed to collect just enough information to classify the training sites according to the National Vegetation Classification System (NVCS). Consequently, we spend 5 minutes or less characterizing each site. We do not have time to collect the amount of ecological and floristic detail characteristic of most vegetation studies. We want to adequately characterize the dominant species and their approximate proportions and delineate the training site as quickly as possible. We cannot afford to spend 30 minutes at one site puzzling over unknown or rare species or precisely locating training site boundaries.
Please refer to the Access database and the Field Training Maunal for full details of the methodologies used to collect field data and for explanations of the attributes collected at each training site.
Purpose:: These data were used to statistically associate plant community labels with Landsat 7 ETM+ imagery and 30-meter digital elevation models to produce land cover maps for the Nevada region of responsibility.

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: November 2003

Currentness_Reference: ground condition

Status:

Progress: Complete
Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -120.932493
East_Bounding_Coordinate: -112.340366
North_Bounding_Coordinate: 42.929037
South_Bounding_Coordinate: 34.015732

Keywords:

Theme:

Theme_Keyword_Thesaurus: unknown
Theme_Keyword: land cover
Theme_Keyword: ground truth
Theme_Keyword: plant communities

Place:

Place_Keyword: Nevada
Place_Keyword: Arizona
Place_Keyword: Utah

Access_Constraints: none

Use_Constraints: none

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Todd Sajwaj
Contact_Organization: Lockheed-Martin Environmental Services Office

Contact_Position: Research Scientist

Contact_Address:

Address_Type: mailing and physical address
Address: 1050 E. Flamingo Rd., Suite E-120
City: Las Vegas
State_or_Province: Nevada
Postal_Code: 89119
Country: USA

Contact_Voice_Telephone: 702.897.3283

Contact_Facsimile_Telephone: 702.897.6640

Contact_Electronic_Mail_Address: tsajwaj@lmepo.com

Native_Data_Set_Environment:

Microsoft Windows 2000 Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 8.2.0.700

Data_Quality_Information:

Logical_Consistency_Report:

Please refer to the Access database and the Field Training Maunal for full details of the methodologies used to collect field data and for explanations of the attributes collected at each training site.

Completeness_Report:

Lineage:

Process_Step:

Process_Description: Metadata imported.
Source_Used_Citation_Abbreviation: D:\NevadaDataBrowser\downloads\gap_train\nv_train\metadata.xml

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 17121

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Label point
Point_and_Vector_Object_Count: 17294

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 17268

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Point
Point_and_Vector_Object_Count: 4

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Albers Conical Equal Area

Albers_Conical_Equal_Area:

Standard_Parallel: 29.500000
Standard_Parallel: 45.500000
Longitude_of_Central_Meridian: -96.000000
Latitude_of_Projection_Origin: 23.000000
False_Easting: 0.000000
False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.002048
Ordinate_Resolution: 0.002048

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: nv_complete

Attribute:

Attribute_Label: FID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI