# Virginia Natural Landscape Assessment (VaNLA), Natural Landscape Blocks

Metadata also available as

## Metadata:

- Identification_Information
- Data_Quality_Information
- Spatial_Data_Organization_Information
- Spatial_Reference_Information
- Entity_and_Attribute_Information
- Distribution_Information
- Metadata_Reference_Information

Identification_Information:
  Citation:
    Citation_Information:
      Originator: Virginia Department of Conservation and Recreation
      Publication_Date: 20070110
      Title:
        Virginia Natural Landscape Assessment (VaNLA), Natural Landscape Blocks
      Geospatial_Data_Presentation_Form: vector digital data
      Online_Linkage: \\WS962\C$\WorkSpace\1_VANLA_Products2\nlbs_20070110_l83.shp
  Description:
    Abstract:
      The Virginia Natural Landscape Assessment (VaNLA), a component of the Virginia Conservation Lands Needs Assessment (VCLNA), is a landscape-scale GIS analysis for identifying, prioritizing, and linking natural habitats in Virginia. Using land cover data derived from satellite imagery, the VaNLA identifies unfragmented natural habitats called cores, large patches of natural land cover (mainly upland forests and forested wetlands, but also included are marshes, beaches, and dunes) with at least 100 acres of interior conditions. Interior conditions begin 100 meters inward from patch edges. Cores are supported and buffered by Natural Landscape Blocks (NLB), which are formed by aggregating cores and adding adjacent natural land cover.
    Purpose:
      The VaNLA generates fundamental ecological data layer for land and natural resources conservation in Virginia.
  Time_Period_of_Content:
    Time_Period_Information:
      Single_Date/Time:
        Calendar_Date: circa 2000
    Currentness_Reference: ground condition
  Status:
    Progress: In work
    Maintenance_and_Update_Frequency: As needed
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -84.230479
      East_Bounding_Coordinate: -75.042322
      North_Bounding_Coordinate: 39.761603
      South_Bounding_Coordinate: 36.161630
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus:
        REQUIRED: Reference to a formally registered thesaurus or a similar authoritative source of theme keywords.
      Theme_Keyword: Virginia Natural Landscape Assessment
      Theme_Keyword: VaNLA
  Access_Constraints:
    REQUIRED: Restrictions and legal prerequisites for accessing the data set.
  Use_Constraints:
    REQUIRED: Restrictions and legal prerequisites for using the data set after access is granted.
  Point_of_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Joseph T. Weber
        Contact_Organization: Department of Conservation and Recreation
      Contact_Position: Natural Heritage GIS Projects Manager/Conservation Biologist
      Contact_Voice_Telephone: (804) 371-2545
      Contact_Facsimile_Telephone: (804) 371-2674
      Contact_Electronic_Mail_Address: joseph.weber@dcr.virginia.gov
      Hours_of_Service: 7:30 AM - 4:15 PM
  Native_Data_Set_Environment:
    Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.1.1332
  Cross_Reference:
    Citation_Information:
      Originator: Virginia Department of Conservation and Recreation
      Publication_Date: 20070110
      Title:
        Virginia Natural Landscape Assessment (VaNLA), Natural Landscape Blocks

Data_Quality_Information:
  Lineage:
    Process_Step:
      Process_Description:
        The study area includes the entire commonwealth of Virginia and a 20-mile buffer around the state. This large buffer was selected to prevent truncation of cores and corridors that cross the state boundary and to facilitate edge matching to similar projects conducted in adjacent states. The Virginia Department of Conservation and Recreation contracted with the University of Maryland (UMD) to develop a land cover layer for the entire state from Landsat Thematic Mapper satellite imagery. The final product, named RESAC 2000, was derived from imagery dating from 1999 to 2001. RESAC 2000 has 21 classes, nine of which represent natural land covers: Barren, Deciduous Forests, Evergreen Forests, Mixed Forests, Deciduous Wooded Wetlands, Evergreen Wooded Wetlands, Emergent Herbaceous Wetlands, Mixed Wetlands, and Natural Grass. An overall thematic accuracy of 90% was reported for this layer. The resolution of this layer is 30-meters, square. The RESAC 2000 layer had only a very small buffer around the state, ergo additional imagery was acquired for coverage of the entire study area. Imagery from the Chesapeake Bay Resource Lands Assessment (also developed by UMD), National Land Cover Data (NLCD) 2001, and one piece of NLCD 1992 were merged to RESAC 2000. The NLCD classifications were cross-walked to match RESAC 2000 and all images were projected to Lambert Conformal Conic before merging. Despite the high reported accuracy of RESAC 2000, there were several important classification errors that needed to be corrected. An accuracy assessment utilizing a five-percent random sample of the Natural Grass class revealed that it almost always represented hayfield or pasture, therefore this class was reclassified to agriculture. There were also maritime grass communities and marshes that were misclassified as agriculture. The marshes were corrected using National Wetlands Inventory (NWI) data, after excluding farmed wetlands, and the maritime grasses were reclassified to a new class of the same name using high-resolution photography to confirm the occurrences were not agriculture. Beaches and dune areas were in the Barren class of RESAC 2000. In order to extract these important natural land covers, undeveloped beaches and dunes were digitized from high-resolution aerial photography dated 2002 (Virginia Base Mapping Program) and the resulting polygons were used to reclassify these areas to a new class named Undeveloped Beaches/Dunes. The resulting layer is known as VANLA Land Cover. The VANLA Land Cover was used to develop the VANLA cores and Natural Landscape Blocks (NLBs). See metadata for the cores layer for more information about cores development. NLBs are slightly fragmented areas of natural cover containing one or more cores that are bounded by major roads and gaps of anthropogenic land cover at least 100 meters across. NLBs buffer cores with contiguous natural cover. NLBs were developed using natural land covers from the land cover layer and eliminating areas of detected and estimated human disturbance (e.g. roads, residential areas, and other developed lands). The following land cover classes were extracted from the VaNLA Land Cover and reclassified as natural land: Deciduous Forests, Evergreen Forests, Mixed forests, Deciduous Wooded Wetlands, Evergreen Wooded Wetlands, Emergent Herbaceous Wetlands, Mixed Wetlands, Undeveloped Beaches/Dunes, and Maritime Grasses. Each patch of natural land was buffered by one pixel, thereby closing gaps less than two pixels across. From the resulting layer, natural land was eliminated where it coincided with major roads, developed lands buffered by one pixel derived from VaNLA Land Cover, high-density road areas buffered by 142 meters that were developed from a focal sum analysis of the VDOT roads layer, and road intersections and terminuses buffered by 100 meters that were developed from the VDOT roads layer. The interior areas of the resulting patches were identified and then only those interior areas that intersected cores were retained. The 100-meters edge transitions were added back in and "donut holes" less than 100 acres were patched to produce the final NLBs. The NLBs were stratified by the largest core or habitat fragment each contained, resulting in the following types of NLBs: large-core NLBs, medium-core NLBs, small-core NLBs, and habitat-fragment NLBs. A unique numeric identifier was assigned to each NLB. The NLB IDs and NLB type attributes can be found in the NLB layer and in the cores layer. Most of the above steps were performed in Grid 9.1 and 9.2, followed by conversion to shapefile in ArcMap 9.2.

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: 10754

Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Map_Projection:
        Map_Projection_Name: Lambert Conformal Conic
        Lambert_Conformal_Conic:
          Standard_Parallel: 37.000000
          Standard_Parallel: 39.500000
          Longitude_of_Central_Meridian: -79.500000
          Latitude_of_Projection_Origin: 36.000000
          False_Easting: 0.000000
          False_Northing: 0.000000
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: coordinate pair
        Coordinate_Representation:
          Abscissa_Resolution: 0.000000
          Ordinate_Resolution: 0.000000
        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: nlbs_20070110_l83
    Attribute:
      Attribute_Label: FID
      Attribute_Definition: Internal feature number.
      Attribute_Definition_Source: ESRI
      Attribute_Domain_Values:
        Unrepresentable_Domain:
          Sequential unique whole numbers that are automatically generated.
    Attribute:
      Attribute_Label: Shape
      Attribute_Definition: Feature geometry.
      Attribute_Definition_Source: ESRI
      Attribute_Domain_Values:
        Unrepresentable_Domain: Coordinates defining the features.
    Attribute:
      Attribute_Label: NLB_ID
      Attribute_Definition: This field contains the unique numberic identifier for each NLB
    Attribute:
      Attribute_Label: NLB_TYPE
      Attribute_Definition: This field identifies the type of VANLA Natural Landscape Block
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: 1
          Enumerated_Domain_Value_Definition: Large-core NLB
        Enumerated_Domain:
          Enumerated_Domain_Value: 2
          Enumerated_Domain_Value_Definition: Medium-core NLB
        Enumerated_Domain:
          Enumerated_Domain_Value: 3
          Enumerated_Domain_Value_Definition: Small-core NLB
        Enumerated_Domain:
          Enumerated_Domain_Value: 4
          Enumerated_Domain_Value_Definition: Habitat-fragment NLB

Distribution_Information:
  Resource_Description: Downloadable Data
  Distribution_Liability:
    Although all data referred to in this documentation have been used by VADCR, no warranty, expressed or implied, is made by VADCR or the original data sources as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by VADCR in the use of these data. Users must assume responsibility to determine appropriate use of these data. VaNLA feature boundaries are not to be used for legal definitions of these areas. Please contact the proper agency or organization with questions concerning ancillary data sets used in, but not created by, the VaNLA. The re-distribution of this dataset for profit is prohibited.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Transfer_Size: 127.254

Metadata_Reference_Information:
  Metadata_Date: 20070119
  Metadata_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Joseph T. Weber
        Contact_Organization: Department of Conservation and Recreation
      Contact_Position: Natural Heritage GIS Projects Manager/Conservation Biologist
      Contact_Address:
        Address_Type:
          REQUIRED: The mailing and/or physical address for the organization or individual.
        City: REQUIRED: The city of the address.
        State_or_Province: REQUIRED: The state or province of the address.
        Postal_Code: REQUIRED: The ZIP or other postal code of the address.
      Contact_Voice_Telephone: (804) 371-2545
      Contact_Facsimile_Telephone: (804) 371-2674
      Contact_Electronic_Mail_Address: joseph.weber@dcr.virginia.gov
      Hours_of_Service: 7:30 AM - 4:15 PM
  Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
  Metadata_Time_Convention: local time
  Metadata_Extensions:
    Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
    Profile_Name: ESRI Metadata Profile

Generated by `mp` version 2.8.6 on Fri Jan 19 16:34:30 2007