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USGS:Biology arrow icon Biological Informatics Program arrow icon Vegetation Characterization Program arrow icon Rock Creek Park arrow icon Spatial Vegetation Data FAQ Metadata

Spatial Vegetation Data FAQ Metadata

Frequently-anticipated questions:

What does this data set describe?

Title: Rock Creek Park Vegetation Mapping Project - Spatial Vegetation Data
Abstract:
The National Park Service (NPS), in conjunction with the Core Science Systems (CSS) of the U.S. Geological Survey (USGS), has implemented a program to "develop a uniform hierarchical vegetation methodology" at a national level. The program will also create a geographic information system (GIS) database for the parks under its management. The purpose of the data is to document the state of vegetation within the NPS service area during the 1990's, thereby providing a baseline study for further analysis at the Regional or Service-wide level. Aerial Information Systems (AIS) was subcontracted by Environmental Systems Research Institute (ESRI), the prime contractor, to perform the photointerpretation for the program. ESRI subcontracted The Nature Conservancy (TNC) to conduct the field sampling effort and to support the development of the National Standard Classification.
Supplemental_Information:
Rock Creek is one of the largest forested urban parks in the United States, with more the ¾ of the park's approximately 2,760 acres covered by mature deciduous forest. A significant portion of this forest is second growth, with a moderately high diversity in canopy and understory species. Rock Creek Park is made up of steep canyons and side slopes that bisect several significant east-west trending ridgelines. The park descends along the fall line through numerous small rapids along the creek. Rock Creek itself, descends over 150' from the state line to its confluence with the Potomac River. Flood plain development is fairly restrictive, limited primarily to Rock Creek itself. Broad Branch, the main tributary to Rock Creek within the park, flows southeasterly and joins Rock Creek towards the southern portion of the park. At the confluence, the park boundary significantly narrows in its east-west extent. All sections are accessible either by automobile or by hiking. Most portions of the park are accessible through short hikes, usually under one mile. Gradients above the floodplain are surprisingly steep, and make for some moderate hiking. For purposes of vegetation mapping, the park was divided into four sections pertaining primarily to its location on the fall line between the coastal plain and piedmont. The park was further divided into the main portion of the park (containing Rock Creek), and the various outliner portions of the park to the east and west.
  1. How should this data set be cited?

    Air Survey Corporation Sterling, Virginia, 19961029, Rock Creek Park: 1.0 Unknown, Air Survey Corporation, Sterling Virginia.

    Online Links:

    Other_Citation_Details: The aerial photography is CIR 1:6,000 scale.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: 77.1
    East_Bounding_Coordinate: 77
    North_Bounding_Coordinate: 38.98333
    South_Bounding_Coordinate: 38.9
    Description_of_Geographic_Extent:
    The park is located on the fall line between the Atlantic coastal plain and the piedmont. The main portion of the park is bounded on the north by the Maryland State line and on the south by the Virginia State line. Its western edge follows along Oregon Avenue, and it is bounded on the east by 16th Street NW. The western outlying portions of the Park extend to and slightly beyond Nebraska Avenue NW. The eastern outlying portions extend from 16th Street NW to the junction of US Highway 1 and the Maryland border.

  3. What does it look like?

    <http://biology.usgs.gov/npsveg/rocr/images/rocrvegmap.pdf> (PDF)
    Graphic in map composition layout

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

    Calendar_Date: 29-Oct-1996
    Currentness_Reference: Source_Photography_Date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: image

  6. How does the data set represent geographic features?

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

      Indirect_Spatial_Reference:
      The ecology field sites were digitized to indicate the area for which a TNC ecologist conducted an ecological field sampling.
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point

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

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 18
      Transverse_Mercator:
      Longitude_of_Central_Meridian: -180
      Latitude_of_Projection_Origin: -90
      False_Easting: 50000
      False_Northing: 0
      Scale_Factor_at_Central_Meridian: 0.9996

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 1
      Ordinates (y-coordinates) are specified to the nearest 1
      Planar coordinates are specified in Meters

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodedic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257.

      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 1
      Altitude_Distance_Units: Feet
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview:
    The system is organized hierarchically to support conservation and resource stewardship applications across multiple scales. The upper levels of the hierarchicy are based on the physical form or structure of the vegetation (physiognomy) and have been refined from the international standards developed by the United Nations Educational, Scientific, and Cultural Organization (UNESCO). The two most detailed levels of the hierearchy are based on the species composition of the existing vegetation (floristics) and reflect the phyto-sociological standards that were originally developed by European ecologists. The vegetation classification is continually advanced through the collection and analysis of new field data and will be greatly strengthened during the course of the USGS-NPS mapping efforts. National Park Service/Core Science Systems Vegetation Inventory and Mapping Program for Rock Creek Park,Washington DC, Final Community Association Classification, March, 1998. DATA DICTIONARY - ROCK CREEK PARK Data Format Outline: Variable Coverage related variables: Area818F Perimeter818F Veg#45B Veg-id45B Defined variables: Seqno33I Mod44C PI 22I Height11I Density11I TNC 33C Landuse44C Pattern11I Data Dictionary: MOD (Defines the modules corresponding to the DOQQ file name. 6 total - roughly corresponding to the six individual plots) WE4 WW1 WW2 WW3 WW3E WW4 Defines Photointerpretation Signature Type (PI) Non Forest Types: 01=Code not Used 02=Managed grass/lawns 03=Meadow grasslands (native component) 04=Shrub areas (forest edges) 05=Canopy openings (shrubs, vines, some trees) 06=Water 99=Urban/disturbed (see detailed Urban codes in Land Use field) Forest Types: 10=Floodplain areas 11=Ash swamps 12=Oak/beech 13=Mesic oak 14=Dry mesic oak 15=Tulip/oak 16=Tulip 17=Pine/oak 18=Tulip/oak/beech 19=Tulip floodplain 20=Exotic/planted trees with managed grass/lawn Defines Height (HEIGHT) 1=< 0.5 meters 2=0.5-2 meters 3=2-5 meters 4=5-15 meters 5=15-35 meters 6=35-50 meters 7=> 50 meters 9=Not Applicable Defines Density (DENSITY) 1=Closed/Continuous>60% 2=Discontinuous40%-60% 3=Dispersed25%-40% 4=Sparse10%-25% 5=Rare2%-10% 9=Not Applicable Defines Mapping Classification Communities and Variants (TNC) 01=Forest canopy gap 02=Loblolly pine - mixed oak forest Pinus taeda - Quercus (alba, falcata, stellata) Forest [Provisional] 03=Virginia pine - oak forest Pinus virginiana - Quercus (alba, stellata, falcata, velutina) Forest Association 04=Sycamore - green ash forest (floodplain forest) Platanus occidentalis - Fraxinus pennsylvanica Forest 05=Tulip poplar forest Liriodendron tulipifera Forest [Provisional] 06=Chestnut oak forest Quercus (prinus, velutina) / Gaylussacia baccata Forest 07=code not used 08=MIXED OAK/BEECH VARIANT of Beech - white oak / mayapple forest Fagus grandifolia - Quercus alba / Podophyllum peltatum Forest 09=code not used 10=Beech - white oak / mayapple forest (CLASSIC TYPE) Fagus grandifolia - Quercus alba / Podophyllum peltatum Forest 10B=Beech - white oak / mayapple forest (CLASSIC TYPE) beech/tulip component Fagus grandifolia - Quercus alba / Podophyllum peltatum Forest 11=Shrub areas 12=Managed grass/lawns 13=Meadow grasslands 14=Managed grass/lawns with trees 98=Water Defines Land Use (LANDUSE) 1000=Urban 1900=Residential 1910=Commercial and Services 1911=Nature center and planetarium 1912=Horse center; maintenance yard 1913=Park headquarters 1914=Park police 1915=Amphitheater 1916=Mixed park facilities 1917=Center for Urban Ecology 1918=Fort Stevens 1919=Fort Reno Park 1920=Industrial 1930=Transportation, Communications, and Utilities 1931=Road 1932=Parking Area 1940=Industrial and Commercial Complexes 1950=Mixed Urban or Built-up Land 1960=Other Urban or Built-up Land 1961=Community gardens 1962=Golf course 1963=Ball fields 1964=Tennis stadium and/or courts 1965=Tennis courts and gardens 1966=Swim center 1967=Area Under Construction 1968=Cemetery 2000=Agriculture 3000=Natural Vegetation 8000=Water Defines Pattern (PATTERN) 1 = Evenly Dispersed 2 = Clumped / Bunched 3 = Gradational / Transitional 4 = Alternating 9 = Not Applicable FILE SPECIFICATIONS: Coordinate system: NAD83 - Maryland State Plane (zone 4126)
    Entity_and_Attribute_Detail_Citation:
    Grossman, D. Et al. 1994. National Park Service Vegetation Mapping Project, Standardized National Vegetation Classificatrion System 209 pp.

  8. What biological taxa does this data set concern?

    Taxonomy:
    Keywords/Taxon:
    Taxonomic_Keyword_Thesaurus: None
    Taxonomic_Keywords: National Vegetation Classification System
    Taxonomic_System:
    Classification_System/Authority:
    Classification_System_Citation:
    Citation_Information:
    Originator:
    United States Department of the Interior National Biological Survey and National Park Service
    Publication_Date: 19941101
    Title:
    Standardized National Vegetation Classification System
    Edition: Version 1
    Geospatial_Data_Presentation_Form: Classification System
    Series_Information:
    Series_Name: NBS/NPS Vegetation Mapping Program
    Issue_Identification: Final Draft
    Publication_Information:
    Publication_Place: Redlands, California
    Publisher: ESRI
    Other_Citation_Details: Prepared by the Nature Conservancy
    Identification_Reference:
    Citation_Information:
    Originator:
    United States Department of the Interior National Biological Survey and National Park Service
    Publication_Date: 19941101
    Title:
    Standardized National Vegetation Classification System
    Edition: Version 1
    Geospatial_Data_Presentation_Form: Classification System
    Series_Information:
    Series_Name: NBS/NPS Vegetation Mapping Program
    Issue_Identification: Final Draft
    Publication_Information:
    Publication_Place: Redlands, California
    Publisher: ESRI
    Other_Citation_Details: Prepared by the Nature Conservancy
    Taxonomic_Procedures:
    See "Photo Interpretation Report, CSS/NPS Vegetation and Inventory and Mapping Program, Rock Creek Park," October 1, 1998 <http://biology.usgs.gov/npsveg/rocr/rocrpirpt.pdf>
    Taxonomic_Completeness: Complete
    General_Taxonomic_Coverage:
    Vegetation Alliances of the National Vegetation Classification System (October 1995)
    Taxonomic_Classification:
    Taxon_Rank_Name: Kingdom
    Taxon_Rank_Value: Plantae

Who produced the data set?

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

    • Air Survey Corporation Sterling, Virginia

  2. Who also contributed to the data set?

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

    USGS/CSS/Core Science Analytics and Synthesis
    c/o USGS-NPS Vegetation Mapping Program Coordinator
    Denver Federal Center, Building 810, Room 8000, MS 302
    Denver, Colorado 80225

    (303) 202-4220 (voice)
    303-202-4219 (FAX)
    gs-b-npsveg@usgs.gov

Why was the data set created?

Several parks, representing different regions, environmental conditions, and vegetation types, were chosen by CSS to be part of the prototype phase of the program. The initial goal of the prototype phase is to "develop, test, refine, and finalize the standards and protocols" to be used during the production phase of the project. This includes the development of a standardized vegetation classification system for each park and the establishment of photointerpretation, field, and accuracy assessment procedures. Rock Creek Park, established in 1890, was designated as one of the prototype parks. The park is located on the fall line between the Atlantic coastal plain and the piedmont. The main portion of the park is bounded on the north by the Maryland State line and on the south by the Virginia State line. Its western edge follows along Oregon Avenue, and it is bounded on the east by 16th Street NW. The western outlying portions of the Park extend to and slightly beyond Nebraska Avenue NW. The eastern outlying portions extend from 16th Street NW to the junction of US Highway 1 and the Maryland border. The park is noted for having exceptional resources, including six natural resources that maintain its significance within the National Park System. Included in these six natural resources, are three that are directly related to the vegetation of the park. They are: 1) Deciduous forests, 2) Wetlands, and 3) Plant species protected in both Virginia and Maryland. Based on these and other resources, Rock Creek Park is divided up into nine management zones pertaining to vegetation, automobile access, recreation, administration, and cultural resources.

How was the data set created?

  1. What methods were used to collect the data?

    Method 0 of 1
    Type: Field

    The normal process in vegetation mapping is to conduct an initial field reconnaissance, map the vegetation units through photointerpretation, then conduct a field verification. The field reconnaissance visit serves two major functions. First, the photointerpreter keys the signature on the aerial photos to the vegetation on the ground at each signature site. Second, the photointerpreter becomes familiar with the flora, vegetation communities and local ecology that occur in the study area. Park and /or TNC field biologists that are familiar with the local vegetation and ecology of the park are present to help the photointerpreter understand these elements and their relationship with the geography of the park.

    Upon completion of the field reconnaissance, photo interpreters delineate vegetation units on mylar that overlay the 9x9 aerial photos. This effort is conducted in accordance with the TNC vegetation classification and criteria for defining each community or alliance. The initial mapping is then followed by a field verification session, whose purpose is to verify that the vegetation units were mapped correctly. Any PI related questions are also addressed during the visit.

    The vegetation mapping at Rock Creek Park in general followed the normal mapping procedure as described above. However, a TNC vegetation classification did not exist for Rock Creek Park at the time the initial delineations commenced. The TNC ecologist and AIS photo interpreters worked together to develop a temporary signature key which addressed what was known at the time. Unlike most parks, no existing plot data was available to create an interim classification.

    Reference:

  2. From what previous works were the data drawn?

    ASC (source 1 of 1)
    Air Survey Corporation Sterling, Virginia, 19961029, Rock Creek Park: 1.0 Unknown, Air Survey Corporation, Sterling Virginia.

    Online Links:

    Other_Citation_Details: The aerial photography is CIR 1:6,000 scale.
    Type_of_Source_Media: CIR Aerial Photography
    Source_Scale_Denominator: 12000
    Source_Contribution: None

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

    Date: 01-Oct-1998 (process 1 of 3)
    See Methodology Description above.

    Data sources used in this process:

    • ASC

    Date: 01-Jun-1998 (process 2 of 3)
    The following continues to describe the tasks performed and methodologies used by Aerial Information Systems (AIS) during the vegetation data compilation for Rock Creek Park. DATA CONVERSION: Typically, the first step of the data conversion process is the Manual rectification was conducted by attaching a new mylar overlay to the base. The photo signature delineation units were transferred to the overlay through local registration of the photos with the attached photo signature delineation overlay. Existing orthophotography for Rock Creek Park was created from photos flown in leaf off conditions. Although this allowed greater ease for viewing features such as roads in forest canopies, it proved difficult to register vegetation from leaf on photography to the early spring leaf off orthophotography. A small area of the photo was registered to the base at a time. By matching photo image to orthophoto image, the delineations were transferred to the base overlay. Because the parallax of the photo differs from that of the orthophoto base, care was required in transfer. Inconsistent stretching or shortening of the images was common from the photo to the base. When one area was completed, the photo was shifted to register to another small area. The process continued until the manual rectification and transfer of polygons was complete. The codes for PI signature type, height, density, and community type were transferred from the corresponding photo overlays.

    Date: 01-Oct-1998 (process 3 of 3)
    FIELD RECONNAISSANCE EFFORT: A three day photointerpretation field reconnaissance effort was conducted in May 1997 (see section III) to tie the photo signatures delineated on the aerial photographs with units evident on the ground. The field crew consisted of Eden Crane and Sue Salmons (park biologists), Virginia Crouch (Heritage biologist), Julie Lundgen (TNC ecologist) and John Menke (AIS photointerpreter).

    Prior to the field reconnaissance effort, several in-house preparations were performed in order to facilitate a more organized trip. Each photo was prepared with a separate field overlay. Locational features (roads, buildings, etc) were drafted onto the overlays. Each photo was reviewed and field transect sites were chosen representing different signatures types, geographic variables (% slope, aspect, shape of the slope, elevation), and other abiotic variables noted on the photography. These sites were drafted onto the field overlays with notations to each site as needed. Multiple siteswere chosen to provide alternatives if one or more sites proved inaccessible.

    The field crew conducted on-site investigations over the three-day period. During the field visit, the photointerpreter worked with the field biologists to identify the plant species, preliminary vegetation communities, and their associated photo signatures throughout the park. Field site numbers were annotated directly onto the photo field overlay, thereby correlating the field site to a specific location and photo signature. A field notebook was used to record pertinent information (canopy dominance, understory species present, abiotic features, disturbance history) for each site visited. Several ground photos were taken at selected locations that were later tied back to the aerial photographs and the field sites. Sites not previously identified on the photos were also visited. These sites included areas between initially selected sites, areas of noteworthy or unusual significance as determined by park personnel, and areas the photointerpreter deemed important in transit from site to site.

  4. What similar or related data should the user be aware of?

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

  1. How well have the observations been checked?

    Code verification involved running each coverage attribute file through a series of ARC/INFO commands that checked for invalid codes. These commands produced listings that aided in identifying abnormal codes. The errors were checked against the vegetation delineation and attribute overlays. Corrections were made to the listings and input into the database. ESRI produced a plot of the converted spatial data and sequence numbers (label I.D.s) for the manuscript. The plot was checked by AIS for cartographic quality of the arcs defining the polygon features and the accuracy of the label I.D. assignments. The plot was overlaid to the manuscript map to verify that the scanned data was not distorted beyond .02 map inches. Other problems were noted on the plots, such as overshoots and undershoots, missing lines, premature convergence of polygon boundary lines that intersected arcs at acute angles, and incorrect sequence number assignments. ESRI produced code verification plots of the community association codes, height and density codes, and land use code attributes. The plots were checked for coding errors that may have occurred during the polygon attribute encoding step. The plots were overlaid on the manuscript map with attached corresponding code attribute overlay created in the manual rectification step. Code changes were noted on the plot. The edited plots were delivered back to ESRI for correction of the attribute files. Processors conducted interactive ARCEDIT sessions to make the necessary corrections to the coverages.

  2. How accurate are the geographic locations?

    Unknown. The positional accuracy of the base digital ortho image is not known. It is assumed the map meets National Map Accuracy Standards.

  3. How accurate are the heights or depths?

    Unknown. The positional accuracy of the base digital ortho image is not known. It is assumed the map meets National Map Accuracy Standards.

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

    All data that can be photointerpreted is also digitized. This includes alliance/association classes, surface water, and unvegetated/landuse.

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

    All polygon features are checked for topology using the ARC/INFO software. Each polygon begins and ends at the same point with the node feature. All nodes are checked for error so that there are no dangling features. There are no duplictae lines or polygons. All nodes will snap together and close polygons based on a specific tolerance. If the node is not within the tolerance, it is adjusted manually. The test for logical consistency are performed in ARC/INFO.

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:
Any person using the information presented here should fully understand the data collection and compilation procedures, as described in these metadata, before beginning analysis. The burden for determining fitness for use lies entirely with the user. For purposes of publication or dissemination, citations should be given to the U.S. Geological Survey and the National Park Service

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

    USGS/CSS/Core Science Analytics and Synthesis
    c/o USGS-NPS Vegetation Mapping Program Coordinator
    Denver Federal Center, Building 810, Room 8000, MS 302
    Denver, Colorado 80225

    (303) 202-4220 (voice)
    303-202-4219 (FAX)
    gs-b-npsveg@usgs.gov

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

    ROCR Veg Map

  3. What legal disclaimers am I supposed to read?

    The U.S. Geological Survey and the National Park Service shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data and related graphics (if available) are not legal documents and are not intended to be used as such.

    The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. Any related graphics (if available) are intended to aid the data user in acquiring relevant data; it is not approriate to use the related graphics as data.

    The U.S. Geological Survey and the National Park Service gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. It is strongly recommended that these data are directly acquired from an U.S. Geological Survey and National Park Service servers and not indirectly through other sources which may have changed the data in some way. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the utility of the data on another system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. Mention of trade names or commercial products in this metadata report does not constitute endorsement or recommendation for use by the U. S. Department of the Interior, U. S. Geological Survey and National Park Service.

  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: Feb-2001
Last Reviewed: 08-Jun-2010
Metadata author:
USGS/CSS/Core Science Analytics and Synthesis
c/o USGS-NPS Vegetation Mapping Program Coordinator
Denver Federal Center, Building 810, Room 8000, MS 302
Denver, Colorado 80225

(303) 202-4220 (voice)
303-202-4219 (FAX)
gs-b-npsveg@usgs.gov

Metadata standard:
FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata (FGDC-STD-001.1-1999)
Metadata extensions used:

Generated by mp version 2.9.12 on Tue Jun 08 12:55:03 2010
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