Shorelines of the Western Beaufort Sea, Alaska coastal region (Colville River to Point Barrow) used in shoreline change analysis

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Frequently anticipated questions:

What does this data set describe?

Title:
Shorelines of the Western Beaufort Sea, Alaska coastal region (Colville River to Point Barrow) used in shoreline change analysis
Abstract:
This dataset includes shorelines from 65 years ranging from 1947 to 2012 for the north coast of Alaska between the Colville River and Point Barrow. Shorelines were compiled from topographic survey sheets (T-sheets; National Oceanic and Atmospheric Administration (NOAA)), aerial orthophotographs (U.S. Geological Survey (USGS), National Aeronautics and Space Administration (NASA), and lidar elevation data(USGS). Historical shoreline positions serve as easily understood features that can be used to describe the movement of beaches through time. These data are used to calculate rates of shoreline change for the U.S. Geological Survey's National Assessment of Shoreline Change Project. Rates of long-term and short-term shoreline change were generated in a GIS using the Digital Shoreline Analysis System (DSAS) version 4.3. DSAS uses a measurement baseline method to calculate rate-of-change statistics. Transects are cast from the reference baseline to intersect each shoreline, establishing measurement points used to calculate shoreline change rates.
Supplemental_Information:
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology.
  1. How might this data set be cited?
    Gibbs, Ann E., Ohman, Karin A., Coppersmith, Ryan, and Richmond, Bruce M., 2017, Shorelines of the Western Beaufort Sea, Alaska coastal region (Colville River to Point Barrow) used in shoreline change analysis: data release 10.5066/F72Z13N1, U.S. Geological Survey, Coastal and Marine Geology Program, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz and Menlo Park, CA.

    Online Links:

    This is part of the following larger work.

    Gibbs, Ann E., Ohman, Karin A., Coppersmith, Ryan, and Richmond, Bruce M., 2017, National Assessment of Shoreline Change: A GIS compilation of Updated Vector Shorelines and Associated Shoreline Change Data for the North Coast of Alaska, U.S. Canadian Border to Icy Cape: data release 10.5066/F72Z13N1, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -156.601685192
    East_Bounding_Coordinate: -151.368140772
    North_Bounding_Coordinate: 71.389682129
    South_Bounding_Coordinate: 70.4098563939
    Description_of_Geographic_Extent:
    North coast of Alaska between the Colville River and Point Barrow
  3. What does it look like?
    WestBeaufortExtent.jpg (JPEG)
    Map of the West Beaufort subregion of the north coast of Alaska shoreline change assessment area.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1947
    Ending_Date: 2012
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
  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 (809)
    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 0.0196079359. Longitudes are given to the nearest 0.0574496603. Latitude and longitude values are specified in Decimal seconds. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    Attribute Table
    Table containing attribute information associated with the data set. (Source: Producer defined)
    OBJECTID
    Unknown (Source: Producer defined)
    Range of values
    Minimum:1
    Maximum:809
    DATE_
    Date of survey (MM/DD/YYYY), as indicated on source material from which shoreline position was digitized. A default date of 07/01 was assigned to shorelines where only the year was known (month and day unknown). Using July, the mid-point month of the calendar year, minimizes the potential offset to the actual shoreline date by a maximum of six months. (Source: Producer defined)
    Range of values
    Minimum:07/01/1947
    Maximum:08/13/2012
    Year_
    Year of survey (YYYY) as indicated on source material from which shoreline position was digitized. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1947
    Maximum:2012
    Uncy
    Total shoreline position uncertainty, in meters. Actual shoreline position is within the range of this value. The uncertainty was determined by equation 1 in Gibbs and Richmond (2017). (Source: U.S. Geological Survey)
    Range of values
    Minimum:6
    Maximum:16
    Default_D
    A binary value given to differentiate between shorelines that have known month and day attributes (Default_D = 0) and those that use the default value of 07/01 when only the year is known (Default_D = 1). (Source: U.S. Geological Survey)
    ValueDefinition
    0Shoreline that has a known month, day, and year attribute
    1Shoreline that has a known year but not a month or day attribute
    Source
    Agency that provided shoreline feature and the data source used to digitize shoreline feature. (Source: U.S. Geological Survey)
    ValueDefinition
    NASA, Alaska High Altitude PhotographyOrthorectified Alaska high altitude photography mosaics
    NOAA, T-SheetNational Oceanographic and Atmospheric Administration Topographic Sheets
    USGS, DOQQU.S. Geological Survey Digital Orthophoto Quarter Quandrangle orthophotgraphy
    USGS, LidarDigital elevation models derived from lidar elevation data
    Source_a
    Specific source ID of data used to digitize shoreline feature. (Source: U.S. Geological Survey) Source data IDs are assigned by the data providers
    Shape_Leng
    Length of shoreline segment in meters (Source: Esri)
    Range of values
    Minimum:25.255075939
    Maximum:31027.8295074
    Entity_and_Attribute_Overview:
    The entity and attribute information provided here describes the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the data set.
    Entity_and_Attribute_Detail_Citation:
    The entity and attribute information was generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Gibbs, Ann E.
    • Ohman, Karin A.
    • Coppersmith, Ryan
    • Richmond, Bruce M.
  2. Who also contributed to the data set?
    U.S. Geological Survey
  3. To whom should users address questions about the data?
    Ann E. Gibbs
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    2885 Mission Street
    Santa Cruz, CA
    USA

    831-460-7540 (voice)
    831-427-4748 (FAX)
    agibbs@usgs.gov

Why was the data set created?

The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and encompasses unique habitats of global significance. Coastal erosion along the north coast of Alaska is chronic, widespread, may be accelerating, and is threatening defense and energy-related infrastructure, natural shoreline habitats, and Native Alaskan communities. There is an increased demand for accurate information regarding past and present shoreline changes across the United States. To meet these national needs, the Coastal and Marine Geology Program of the USGS is compiling existing reliable historical shoreline data along sandy shores of the conterminous United States and parts of Alaska and Hawaii under the National Assessment of Shoreline Change project. There is no widely accepted standard for analyzing shoreline change. Existing shoreline data measurements and rate calculation methods vary from study to study and prevent combining results into state-wide or regional assessments. The impetus behind the National Assessment project was to develop a standardized method of measuring changes in shoreline position that is consistent from coast to coast. The goal was to facilitate the process of periodically and systematically updating the results in an internally consistent manner.

How was the data set created?

  1. From what previous works were the data drawn?
    T-sheets (source 1 of 4)
    National Oceanic and Atmospheric Administration, Unpublished material, Topographic sheets (T-sheets) and Nautical Charts.

    Type_of_Source_Media: Digital Data (.tif)
    Source_Contribution:
    T-sheet imagery was used to delineate Mean-High-Water (MHW) shoreline position
    AHAP (source 2 of 4)
    Arctic Landscape Conservation Cooperative, Unpublished material, Alaska High-Altitude Photography.

    Type_of_Source_Media: Digital Data (.tif)
    Source_Contribution:
    AHAP imagery was used to delineate an instantaneous land-water shoreline position
    DOQQs (source 3 of 4)
    U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, 20060629, Digital Orthophoto Quadrangles: U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, online.

    Online Links:

    Type_of_Source_Media: Digital Data
    Source_Contribution:
    DOQQ orthoimagery was used to delineate an instantaneous land-water shoreline position
    Lidar DEMs (source 4 of 4)
    U.S. Geological Survey (USGS), 2012, LiDAR Scenes: U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, online.

    Online Links:

    Type_of_Source_Media: Digital Data
    Source_Contribution:
    Lidar DEMs were used to delineate an instantaneous land-water shoreline position
  2. How were the data generated, processed, and modified?
    Date: 2009 (process 1 of 8)
    T-sheets were geo-registered using Esri ArcMap software (v9.3) by placing 8-20 well-spaced ground control points (GCP) at gridline intersections and applying a third-order polynomial transformation. Some T-sheets may have required additional coordinate transformation information from NOAA to account for datum offsets between historical datums (USSD) and modern datums (NAD27 or NAD83). Datum transformations were applied to GCP coordinates prior to registration. Total root-mean-square error (RMSE) for the rectification process was maintained below 0.0001 degrees, which is approximately 11 m at this latitude. Typically the resulting RMSE was much lower than 0.0001 degree.
    Date: 2010 (process 2 of 8)
    T-sheet and Nautical chart derived shorelines were projected in Esri's ArcToolbox (v.9.3) Data Management Tools >; Projections and Transformations >; Feature >; Project. Parameters: input projection = geographic (NAD 83); output projection = UTM zone XN (NAD 83; where X is the corresponding UTM zone).
    Date: 2016 (process 3 of 8)
    Vector shorelines were digitized from all data sources using standard editing tools in ArcMap v9.3 or v10.3 using criteria described in Gibbs and Richmond(2015; http://dx.doi.org/10.3133/ofr20151048). Quality assessments were performed, and shorelines were edited to remove any overlap between adjacent shorelines.
    Date: 2016 (process 4 of 8)
    Shorelines from all sources were merged in Esri's ArcToolbox; Data Management Tools > General > Merge to produce a single shoreline file for each UTM zone. The final shoreline dataset was coded with attribute fields Date_, Uncy, Default_D, Year_, Source, Source_a, and Shape_Leng.
    Date: 2016 (process 5 of 8)
    The appended shoreline file was imported into a personal geodatabase in ArcCatalog v10.3 by right-clicking on the geodatabase > Import (feature class) for use with the Digital Shoreline Analysis System (DSAS) v4.3 software to perform rate calculations.
    Date: 2016 (process 6 of 8)
    The shoreline feature class was exported from the personal geodatabase back to a shapefile in Esri's ArcCatalog v10.3 by right-clicking on the shoreline file > Export > To Shapefile (single) for publication purposes.
    Date: 2016 (process 7 of 8)
    The data were projected in Esri's ArcToolbox v10.1 > Data Management Tools > Projections and Transformations > Feature > Project. Parameters: input projection = UTM zone XN (NAD83; where X is the corresponding UTM zone); output projection = geographic coordinates (WGS84); transformation = WGS_1984_(ITRF00)_To_NAD_1983.
    Date: 19-Oct-2020 (process 8 of 8)
    Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Gibbs, A.E., and B.M., Richmond, 2017, National Assessment of Shoreline Change: Summary Statistics for Updated Vector Shorelines and Associated Shoreline Change Data for the North Coast of Alaska, U.S.--Canadian Border to Icy Cape: Open-File Report 2017-1107, U.S. Geological Survey, Reston, VA.

    Online Links:

    Gibbs, Ann E., and Richmond, Bruce M., 2015, National Assessment of Shoreline Change: Historical Shoreline Change along the North Coast of Alaska, U.S.--Canadian Border to Icy Cape: Open-File Report 2015-1048, U.S. Geological Survey, Reston, VA.

    Online Links:

    Thieler, E.R., Himmelstoss, E.A., Zichichi, J.L., and Ergul, A., 2009, Digital Shoreline Analysis System (DSAS) version 4.0 - An ArcGIS extension for calculating shoreline change: Open-File Report 2008-1278, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details: Current version at time of use was 4.3

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

  1. How well have the observations been checked?
    The data provided here are a compilation of shorelines from multiple sources, spanning 65 years. The attributes are based on the requirements of the Digital Shoreline Analysis System (DSAS) software and have gone through a series of quality assurance procedures.
  2. How accurate are the geographic locations?
    Shoreline data have been acquired from 1947 to 2012, the horizontal accuracy of which varies with respect to data source from which the shorelines were digitized and the time period. Shorelines digitized from the 1980s era Alaska High Altitude Photography (AHAP) have an estimated shoreline position uncertainty of plus or minus 10 meters. Shorelines digitized from the 1940s and 1980s era T-sheets have an estimated total shoreline position uncertainty of plus or minus 16 meters. Shorelines digitized from 1997-2007 orthophotographs have an estimated total shoreline position uncertainty of plus or minus 3 or 4 meters. Shorelines generated from 2002 and 2005 USGS Digital Orthophoto Quarter-Quadrangles (DOQQs), and 2009-2012 lidar data have an estimated total shoreline position uncertainty of plus or minus 6 to 10 meters. Please visit the 'Estimation of Shoreline Position Uncertainty' section in Gibbs and Richmond (2017) for a complete explanation of the measurement uncertainties associated with these shorelines.
  3. How accurate are the heights or depths?
    A formal accuracy assessment of the vertical positional information in the data set has either not been conducted, or is not applicable.
  4. Where are the gaps in the data? What is missing?
    This shoreline file is complete and contains all shoreline segments used to calculate shoreline change rates along sections of the north coast of Alaska, between the Colville River and Point Barrow, where shoreline position data were available. These data adequately represented the shoreline position at the time of the survey. Remaining gaps in these data, if any, 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?
    Adjacent shoreline segments do not overlap and are not necessarily continuous. Shorelines were quality checked for accuracy. Any slight offsets between adjacent segments due to georeferencing and digitizing error are taken into account in the uncertainty calculations included in Gibbs and Richmond (2017).

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:
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - Science Base
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    CA

    888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? WestBeaufort_shorelines.shp
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    This zip file contains data available in Environmental Systems Research Institute (Esri) polyline 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.

Who wrote the metadata?

Dates:
Last modified: 19-Oct-2020
Metadata author:
Ann E. Gibbs
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Geologist
2885 Mission Street
Santa Cruz, CA
USA

831-460-7540 (voice)
831-427-4748 (FAX)
agibbs@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/ScienceBase/DR_F72Z13N1/WestBeaufort_shorelines.faq.html>
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