Fall Cankerworm - 2002
GIS FAQs:

fallcank_2002

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Frequently-anticipated questions:

What does this data set describe?

  • Title: fallcank_2002
  • Abstract: This dataset includes polygons of hardwood tree defoliation caused by larvae of the fall cankerworm, a native inchworm. Limited to extensive outbreaks of this insect occur somewhere in Virginia every few years and last from one to several years. They are more common in the mountains, but occur in piedmont and coastal plain areas as well. Polygons are delimited mostly by aerial sketchmapping, but ground surveys are also used. Data for this layer were collected 5/31/02.
  • Supplemental_Information: All defoliation mapped during this survey was moderate to heavy.
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
    • West_Bounding_Coordinate: -79.915303
    • East_Bounding_Coordinate: -77.125227
    • North_Bounding_Coordinate: 39.325852
    • South_Bounding_Coordinate: 37.351381
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    • Calendar_Date: May 2002
    • Currentness_Reference: ground condition
  5. What is the general form of this data set?
    • Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      • This is a Vector data set. It contains the following vector data types (SDTS terminology): G-polygon (58)
    2. What coordinate system is used to represent geographic features?
      • The map projection used is Lambert Conformal Conic.
        • Projection parameters:
          • 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 coordinates are encoded using coordinate pair
        • Abscissae (x-coordinates) are specified to the nearest 0.000512
        • Ordinates (y-coordinates) are specified to the nearest 0.000512
        • Planar coordinates are specified in meters
      • The horizontal datum used is North American Datum of 1983.
        • The ellipsoid used is Geodetic Reference System 80.
        • The semi-major axis of the ellipsoid used is 6378137.000000.
        • The flattening of the ellipsoid used is 1/298.257222.
  7. How does the data set describe geographic features?
    • fallcank_2002 2002 Fall Cankerworm Defoliation
    • FID Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    • Shape Feature geometry. (Source: ESRI) Coordinates defining the features.
    • ACRES Polygon area in acres
    • AREA Polygon Area in square meters
    • SURVEY_TYP Survey Type
      • Ground: Ground Survey
      • Aerial: Aerial Survey
    • COUNTY County within which defoliation poly was mapped

Who produced the data set?

  1. Who are the originators of the data set?(may include formal authors, digital compilers, and editors)
    • Virginia Department of Forestry
  2. Who also contributed to the data set?

    Sketch Mapping was performed by Mike Griffin and Tim Tigner, Pilot was Phil Carpenter. Jason Braunstein digitized the sketch maps.

  3. To whom should users address questions about the data?
    • Jason Braunstein
      Virginia Department of Forestry
      GIS Manager
      900 Natural Resources Drive, Suite 800
      Charlottesville, VA 22903
      434.977.6555 (voice)
      434.296.2369 (FAX)

Why was the data set created?

Defoliation surveys are used to assess potential impact, to facilitate communications with landowners and to help analyze spatial patterns and trends in forest health.

How was the data set created?

  1. From what previous works were the data drawn?
    • (source 1 of 1)
    • Source_Scale_Denominator:100000
  2. How were the data generated, processed, and modified?

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

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    • +/- 170 feet
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?

    Aerial survey of fall cankerworm defoliation in 2002 was limited to the Blue Ridge counties from Greene to Fauquier. Other mapped polygons were detected from ground surveys. Time and other resource limitations prevented surveys of some southwestern mountain areas where periodic fall cankerworm defoliation is common. Heavy defoliation in populated areas rarely goes unreported and it is unlikely that such occurrences were overlooked. For example, a small patch of defoliation by cankerworms in the City of Danville was reported, but not mapped.

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

How can someone get a copy of the data set?

  • Are there legal restrictions on access or use of the data?
    • Access_Constraints: Data are available to all interested parties
    • Use_Constraints: Data are only to be redistributed with accompanying metadata
  1. Who distributes the data set?
    • [Distributor contact information not provided.]
  2. What's the catalog number I need to order this data set?
    • Downloadable Data
  3. What legal disclaimers am I supposed to read?

    This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the sole responsibility of the user.

    While The Virginia Department of Forestry (DOF) has attempted to ensure that this documentation is accurate and reliable, DOF does not assume liability for any damages caused by inaccuracies in these data or documentation, or as a result of the failure of the data or software to function in a particular manner. DOF makes no warranty, express or implied, as to the accuracy, completeness, or utility of this information, nor does the fact of distribution constitute a warranty.

  4. How can I download or order the data?
    • Availability in digital form:
      • Data format:
      • Size: 0.039
    • Cost to order the data:

Who wrote the metadata?

  • Dates: Last modified: 18-Jul-2002
  • Metadata author:
    • Jason Braunstein
      Virginia Department of Forestry
      GIS Manager
      900 Natural Resources Drive, Suite 800
      Charlottesville, VA 22903
      434.977.6555 (voice)
      434.296.2369 (FAX)
  • Metadata standard: FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
  • Metadata extensions used:
    • http://www.esri.com/metadata/esriprof80.html

Generated by http://geology.usgs.gov/tools/metadata/tools/doc/mp.html version 2.7.3 on Thu Jul 18 10:15:21 2002