20250617 06463200 FALSE 20091213 11411800 20091213 11411800 1.0 ESRI ArcCatalog 9.2.6.1500 en The Natural Landscape Assessment (NLA), 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 NLA identifies unfragmented natural habitats called cores, large patches of natural land cover (mainly upland forests and forested wetlands statewide, but also marshes, beaches, and dunes in the coastal plain) with at least 100 acres of interior conditions. Large, medium, and small cores have been identified (see definitions in attribute section), along with a smaller feature type called "habitat fragments" that may be important in the more urban localities. Cores provide habitat for a wide ranges of species, from forest interior-dependent to habitat-generalist species, as well as species that utilize marsh, dune, and beach habitats. Cores also provide benefits in terms of open space, recreation, water quality (including drinking water protection), and carbon sequestration, along with the associated economic benefits of these functions. The NLA generates fundamental ecological data layer for land and natural resources conservation in Virginia. Virginia Department of Conservation and Recreation 20071102 Virginia Natural Landscape Assessment -- Coastal Zone Corridors and Nodes Corridors_AC_sel vector digital data withheld ground condition circa 2000 In work As needed -80.706488 -75.230025 39.463312 36.430528 -103833.136800 367724.066590 55940.745652 384380.750565 Virginia Natural Landscape Assessment VaNLA REQUIRED: Restrictions and legal prerequisites for accessing the data set. REQUIRED: Restrictions and legal prerequisites for using the data set after access is granted. Shapefile Joseph T. Weber Department of Conservation and Recreation Natural Heritage GIS Projects Manager/Conservation Biologist (804) 371-2545 (804) 371-2674 joseph.weber@dcr.virginia.gov 7:30 AM - 4:15 PM ESRI ArcCatalog 9.2.6.1500 Corridors_AC_sel -103833.1368 367724.06659 384380.750565 55940.745652 1 -80.706488 -75.230025 39.463312 36.430528 1 en FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time Joseph T. Weber Department of Conservation and Recreation REQUIRED: The mailing and/or physical address for the organization or individual. REQUIRED: The city of the address. REQUIRED: The state or province of the address. REQUIRED: The ZIP or other postal code of the address. (804) 371-2545 Natural Heritage GIS Projects Manager/Conservation Biologist (804) 371-2674 joseph.weber@dcr.virginia.gov 7:30 AM - 4:15 PM 20091213 http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile ISO 19115 Geographic Information - Metadata DIS_ESRI1.0 dataset Downloadable Data 0.000 0.000 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. 002 withheld Local Area Network 0.000 Shapefile Vector Simple Polygon FALSE 0 FALSE FALSE G-polygon 0 GCS_North_American_1983 NAD_1983_Lambert_Conformal_Conic coordinate pair meters 0.000000 0.000000 Lambert Conformal Conic 37.000000 39.500000 -79.500000 36.000000 0.000000 0.000000 North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 NAD_1983_Lambert_Conformal_Conic 0 Corridors_AC_sel Feature Class 0 FID FID OID 4 0 0 This field contains the Internal Feature Number, a unique sequential number that is automatically generated by ArcGIS 9.1 software. ESRI Sequential unique whole numbers that are automatically generated. Shape Shape Geometry 0 0 0 This field contains the feature geometry, the coordinates defining the features. ESRI Coordinates defining the features. TYPE TYPE String 10 Type of feature -- corridor or node CORRIDORID CORRIDORID Float 19 11 NODEID NODEID Float 19 11 COREID COREID Number 9 EndCore1 EndCore1 Number 9 EndCore2 EndCore2 Number 9 NodeID NodeID Number 9 Contains the node ID, which is equal to the core ID. CorridorID CorridorID Number 9 Contains a unique identifing number for each corridor 20091213 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, which are defined for this analysis as patches of natural cover containing at least 100 acres of interior cover. Interior cover begins 100 meters inward from the patch edge. This 100-meters buffer constitutes the abiotic transition zone following the "three-tree-height" rule (Harris 1984), since fully mature forests in Virginia reach maximum height around 33 meters. The first step in the core development process was to assemble a fragmentation layer that included spatial data for powerlines, pipelines, railroads, and roads. This layer was used to fragment the VANLA Land Cover, thus making a better approximation of the fragmentation in the landscape. Anthropogenic land covers were excluded from the analysis at this point by extracting from the fragmented land cover layer only the following classes and then classifying them as natural cover: Deciduous Forests, Evergreen Forests, Mixed forests, Deciduous Wooded Wetlands, Evergreen Wooded Wetlands, Emergent Herbaceous Wetlands, Mixed Wetlands, Undeveloped Beaches/Dunes, and Maritime Grasses. One pixel width of near-shore open water was added back from the fragmented land cover to the natural cover layer. This prevented narrow stretches of open water less than 60 meters across (two pixel widths) from splitting a core into two or more smaller patches. The interior areas of the patches in the natural cover layer were identified by using distance analysis to calculate the 100-meter abiotic transition zone of each patch. Interior areas greater than or equal to 10 acres were then identified; all patches not meeting this criterion were excluded from further analysis. The abiotic transition zone was added back to the remaining interior areas. These patches were then classified into Large Cores if they had at least 10,000 acres of interior cover, Medium Cores if they had 1,000 to 9,999 acres of interior cover, Small Cores if they had 100 to 999 acres of interior cover, and Habitat Fragments if they had 10 to 99 acres of interior cover. The Habitat Fragments feature type resulted from a pilot study for the VANLA completed in 2004 (Weber & Carter-Lovejoy) which revealed that the 100-acres minimum interior size for cores was too restrictive for urban and some suburban localities. These features may contain natural heritage resources and have utility for recreation, open space, and storm water management, but they are too small or narrow to provide many of the other benefits of cores. Analyses were performed to add many prioritization attributes to the cores and habitat fragments layer. Definitions and justifications for each of these prioritization attributes can be found in the attributes section of these metadata. 20061107 Dataset copied. withheld 20061214 Dataset copied. withheld 20070110 Dataset copied. withheld 20070315 Dataset copied. withheld 20070406 Dataset copied. withheld 20070502 Dataset copied. withheld 20070503 Dataset copied. withheld 20070507 Dataset copied. withheld 20070509 Dataset copied. withheld 20070622 Dataset copied. withheld 20070625 Dataset copied. withheld 20070625 Dataset copied. withheld 20071102 Dataset copied. withheld 20071102 Dataset copied. withheld 20071102 Dataset copied. withheld 20071210 Dataset copied. withheld 20071210 Dataset copied. withheld 20071211 Dataset copied. withheld 20120917 08320600 Dataset copied. withheld 20131031 12315200