norcal2002.shp - Vectorized Cliff Edge of Northern California Derived from 2002 Lidar Source Data

Frequently-asked questions:


What does this data set describe?

Title:
norcal2002.shp - Vectorized Cliff Edge of Northern California Derived from 2002 Lidar Source Data

Abstract:
There are critical needs for a nationwide compilation of reliable cliff edge data.  To meet these needs, the USGS has produced a comprehensive database of digital vector cliff edges by compiling cliff edge positions from pre-existing historical cliff edge databases and by generating historical and modern cliff edge data.  Cliff edges are compiled by state and generally correspond to two periods: 1920s-1930s and 1998-2002.  Each cliff edge may represent a compilation of data from one or more sources for one or more dates provided by one or more agencies.  Details regarding source are provided in the 'data quality information' section of this metadata report.  Cliff edge vectors derived from both historic sources (first time period) and modern sources (final time period) represent the cliff edge at the time of the survey.

  1. How should this data set be cited?

    Cheryl Hapke, David Reid, Krystal Green, 2007, norcal2002.shp - Vectorized Cliff Edge of Northern California Derived from 2002 Lidar Source Data: Open-File Report 2006-1112, U.S. Geological Survey, Coastal and Marine Geology Program, U.S. Geological Survey, Pacific Science Center, Santa Cruz, California.

    Online links:
    This is part of the following larger work:

    Cheryl Hapke, David Reid, Krystal Green, Mark Borrelli, 2007, National Assessment of Shoreline Change: Part 4: A GIS Compilation of Vector cliff edges and associated change data for the cliffed shorelines of the California Coast: Open-File Report 2007-1112, U.S. Geological Survey, Coastal and Marine Geology Program, U.S. Geological Survey, Pacific Science Center, Santa Cruz.

    Online links:
  2. What geographic area does the data set cover?

    Bounding coordinates:
    West: -124.443086
    East: -122.965805
    North: 42.001897
    South: 38.245274

  3. What does it look like?

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

    Calendar date: 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):
      • String (1398)

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

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees.

      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?

    NorCal2002
    Vector Cliff Edge from Lidar Overflight
    (Source:
    U.S. Geological Survey
    )

    FID
    Internal feature number.
    (Source:
    Unrepresentable_Domain  Sequential unique whole numbers that are automatically generated.
    )

    Sequential unique whole numbers that are automatically generated.

    Shape
    Internal feature number.
    (Source:
    Unrepresentable_Domain  Sequential unique whole numbers that are automatically generated.
    )

    Coordinates defining the feature.

    ID
    Feature number.
    (Source:
    U.S. Geological Survey
    )

    Range of values
    Minimum: 1
    Maximum: 40677

    DATE_
    Date of Lidar overflight
    (Source:
    U.S. Geological Survey
    )

    Range of values
    Minimum: 20020921
    Maximum: 20021002

    DESCR
    Detailed description of the feature.
    (Source:
    U.S. Geological Survey
    )

    Describes additional characteristics of the feature.

    ACCURACY
    Position accuracy of feature.
    (Source:
    U.S. Geological Survey
    )

    Value Definition
    0
    The accuracy is not given but should be 1.4 meters.

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Who produced the data set?

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


  2. Who also contributed to the data set?

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

    Cheryl Hapke
    U.S. Geological Survey
    Patuxent Wildlife Research Center
    University of Rhode Island
    317 Woodward Hall, Dept. of Geosciences
    Kingston, RI 02881
    USA

    401-874-5532 (voice)
    401-874-2190 (FAX)
    chapke@usgs.gov
    Hours of Service: Monday through Friday, 9 a.m. to 5 p.m., Eastern Standard Time
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Why was the data set created?

Historical cliff erosion is considered to be a crucial element in studying the vulnerability of the national coastline.  These data are used in a cliff erosion analysis for the USGS National Assessment Project.

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How was the data set created?

  1. Where did the data come from?

    Lidar (source 1 of 1)

    Coastal Remote Sensing/Coastal Services Center, 08292005, Aircraft Laser/GPS Mapping of Coastal Topography.: NOAA Coastal Services Center, Charleston, SC.

    Online links:
    Other citation details:
    This data set has been extracted from one much larger. See the URL for the location of this larger data set.

    Type of source media: Lidar Vector Shoreline
    Source contribution:
    USGS/NASA Airborne Topographic Mapper

  2. What changes have been made?

    Date: 2006 (change 1 of 2)
    The USGS in collaboration with NASA, used the NASA Airborne Topographic Mapper (ATM II and III) mounted on a Twin Otter Aircraft to map coastal beaches. The raw data was georeferenced at elevation points every few square meters. The original data from ATM was collected in WGS 84, ITRF 97, in a geographic (lat/long) coordinate system with irregular spacing. The data was then converted to NAD 83 and NAVD 88. The cliff edge generation involved an analysis of shore-normal profiles at 20m intervals alongshore.  The point solutions were connected to produce a continuous vector cliff edge in shapefile format.  A shore-parallel reference line was digitized as a permanent baseline for any future cliff edge generation.  Data were projected to UTM zone 10 NAD27 for statistical analysis in the Digital Shoreline Analysis System (DSAS) software.

    Person responsible for change:
    Cheryl Hapke
    U.S. Geological Survey
    USGS Patuxent Wildlife Research Center
    University of Rhode Island
    Coastal Field Station
    317 Woodward Hall, Dept. of Geosciences
    Kingston, RI 02881
    USA

    401-874-5532 (voice)
    401-874-2190 (FAX)
    chapke@usgs.gov
    Hours of Service: Monday through Friday, 8 a.m. to 5 p.m., Eastern Standard Time

    Date: 20070215 (change 2 of 2)
    Data were projected from UTM zone 10 to geographic
    
    Tool: ArcGIS > ArcToolbox > Toolboxes > Data Management Tools > Project
    
    Command issued:
    ['GCS_North_American_1983',DATUM['D_North_American_1983',SHPERIOD['GRS_1980',6378137.0,298.25722101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]]

    Person responsible for change:
    Emily Himmelstoss
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2262 (voice)
    508-457-2310 (FAX)
    ehimmelstoss@usgs.gov

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

  1. How well have the observations been checked?

    The data supplied here are a compilation of information collected from numerous LIDAR (LIght Detection And Ranging) surveys.  Attribute data was generated once the point solutions from the elevation point data were processed and identified as representing the cliff edge location.  The attributes in this dataset are based on the Digital Shoreline Analysis System (DSAS) version 3.2; An ArcGIS extension for calculating shoreline change (Thieler, E.R., Himmelstoss, E.A., Zichichi, J.L., and Miller, T.M. 2005. U.S. Geological Survey Open-File Report 2005-1304).  The data has gone through a series of QA/QC procedures, and is therefore believed to accurately reflect the data gathered as part of the National Assessment of Shoreline Change Study.

  2. How accurate are the geographic locations?

    The maximum estimated positional error for this cliff edge is 1.4 meters. Please visit our full report on cliff erosion along the Coastline of California (<http://pubs.usgs.gov/of/2007/1133), under the heading  "Uncertainties and Errors", for a complete explanation of the measurement error.

  3. How accurate are the heights or depths?

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

    This cliff edge data adequately represented the cliff edge at the time of the survey.  Remaining gaps in these data, if applicable, are a consequence of non-existing data or existing data that did not meet quality assurance standards.

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

    There is significant agreement of linework between adjacent cliff edges.  Cliff edges were checked for accuracy, but no edgematching attempts were made between adjacent cliff edges even if slight offsets existed.

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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:
Public domain data are freely redistributable with proper metadata and source attribution.  The U.S. Geological Survey (USGS) must be referenced as the originator of the dataset in any future products or research derived from these data.

Distributor 1 of 1

  1. Who distributes the data set?

    U.S. Geological Survey
    Pacific Science Center
    400 Natural Bridges Drive
    Santa Cruz, CA 95060
    USA

    831-427-4450 (voice)
    831-427-4748 (FAX)
    Hours of Service: Monday through Friday, 8 a.m. to 5 p.m., Eastern Standard Time

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

    downloadable data

  3. What legal disclaimers am I supposed to read?

    Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, these data and information are provided with the understanding that they are not guaranteed to be usable, timely, accurate, or complete. Users are cautioned to consider carefully the provisional nature of these data and information before using them for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences. Conclusions drawn from, or actions undertaken on the basis of, such data and information are the sole responsibility of the user.
    
    Neither the U.S. Government nor any agency thereof, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any data, software, information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights.
    
    Trade, firm, or product names and other references to non-USGS products and services are provided for information only and do not constitute endorsement or warranty, express or implied, by the USGS, USDOI, or U.S. Government, as to their suitability, content, usefulness, functioning, completeness, or accuracy.

  4. How can I download or order the data?

    • Availability in digital form:


    • Data format:
      in format SHP (version Unspecified)
      ESRI Polyline Shapefile. The DBF file contains the attribute data in dBASE format. The PRJ file contains the coordinate system information. The SBN and SBX files contain the spatial index of the geospatial data. The SHP file contains the geospatial data. The SHX file contains the index of the geospatial data. The XML file contains the metadata describing the data set.
      Size: 0.348
      Network links:
      http://pubs.usgs.gov/of/2007/1112/NCal.zip
      http://pubs.usgs.gov/of/2007/1112/

    • Cost to order the data: None


  5. Is there some other way to get the data?

  6. What hardware or software do I need in order to use the data set?

    These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.

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Who wrote the metadata?

Dates:
Last modified: 20070319

Metadata author:
Cheryl Hapke
U.S. Geological Survey
USGS Patuxent Wildlife Research Center
University of Rhode Island
Coastal Field Station
317 Woodward Hall, Dept. of Geosciences
Kingston, RI 02881
USA

401-874-5532 (voice)
401-874-2190 (FAX)
chapke@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Metadata extensions used:
  • http://www.esri.com/metadata/esriprof80.html

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