Onshore/offshore baseline for Nantucket coastal region generated to calculate shoreline change rates for the Nantucket coastal region including the Nantucket Sound- and Atlantic Ocean- facing coasts of Nantucket, Muskeget and Tuckernuck Islands (Nantucket_baseline.shp)

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Frequently anticipated questions:

What does this data set describe?

Title:
Onshore/offshore baseline for Nantucket coastal region generated to calculate shoreline change rates for the Nantucket coastal region including the Nantucket Sound- and Atlantic Ocean- facing coasts of Nantucket, Muskeget and Tuckernuck Islands (Nantucket_baseline.shp)
Abstract:
Due to continued coastal population growth and increased threats of erosion, current data on trends and rates of shoreline movement are required to inform shoreline and floodplain management. The Massachusetts Office of Coastal Zone Management launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates at 40-meter intervals along ocean-facing sections of the Massachusetts coast.
The Coastal and Marine Geology Program of the U.S. Geological Survey (USGS) in cooperation with the Massachusetts Office of Coastal Zone Management, has compiled reliable historical shoreline data along open-facing sections of the Massachusetts coast under the Massachusetts Shoreline Change Mapping and Analysis Project 2013 Update. Two oceanfront shorelines for Massachusetts (approximately 1,800 km in total length) were (1) delineated using 2008/09 color aerial orthoimagery, and (2) extracted from topographic LIDAR datasets (2007) obtained from NOAA's Ocean Service, Coastal Services Center. The new shorelines were integrated with existing Massachusetts Office of Coastal Zone Management and USGS historical shoreline data in order to compute long- and short-term rates using the latest version of the Digital Shoreline Analysis System (DSAS).
Supplemental_Information:
Cross-referenced citations are applicable to the dataset as a whole.
  1. How might this data set be cited?
    U.S. Geological Survey, 2013, Onshore/offshore baseline for Nantucket coastal region generated to calculate shoreline change rates for the Nantucket coastal region including the Nantucket Sound- and Atlantic Ocean- facing coasts of Nantucket, Muskeget and Tuckernuck Islands (Nantucket_baseline.shp): Open-File Report 2012-1183, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Smith, Theresa L., Himmelstoss, Emily A., and Thieler, E. Robert, 2013, Massachusetts Shoreline Change Project: A GIS Compilation of Vector Shorelines and Associated Shoreline Change Data for the 2013 update: Open-File Report 2012-1183, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.312287
    East_Bounding_Coordinate: -69.959011
    North_Bounding_Coordinate: 41.394558
    South_Bounding_Coordinate: 41.236710
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2013
    Currentness_Reference:
    publication date
  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 (17)
    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?
    Nantucket_baseline
    Vector reference baselines (Source: U.S. Geological Survey)
    FID
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    ID
    Field required by the Digital Shoreline Analysis System (DSAS) software. DSAS uses this value to determine the ordering sequence of transects when the baseline feature contains multiple segments. Individual segments are numbered sequentially alongshore. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1
    Maximum:17
    OFFshore
    This field is required if a combination of onshore and offshore baselines are used with the DSAS software. The name of this field is specific, meaning that the field must be called OFFshore and is case-sensitive. It provides positioning information of the baseline relative to the location of the shorelines being used for rate calculations allowing for positive and negative values to appropriately indicate accretion and erosion in the reported rates. (Source: U.S. Geological Survey)
    ValueDefinition
    1The baseline segment is positioned offshore or seaward of the input shorelines.
    0The baseline segment is positioned onshore or landward of the input shorelines.
    CastDir
    This field is required in conjunction with OFFshore if a combination of onshore and offshore baselines are used with the DSAS software. The name of this field is specific, meaning the field must be called CastDir, and is case sensitive. Transects originate at the baseline and this attribute field indicates which direction (left or right) to cast the transects based on the start to end vertices of the baseline. (Source: U.S. Geological Survey)
    ValueDefinition
    0Transects will be cast to the left of the baseline based on directionality from the start vertex of the baseline segment to the last vertex that the ends line segment.
    1Transects will be cast to the right of the baseline based on directionality from the start vertex of the baseline segment to the last vertex that ends the line segment.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Theresa Smith
    Contract Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 (voice)
    508-547-2310 (FAX)
    theresasmith@usgs.gov

Why was the data set created?

Rates of long-term and short-term shoreline change were computed within a GIS using the Digital Shoreline Analysis System (DSAS) version 4.3, an ArcGIS extension developed by the U.S. Geological Survey. The baseline is used as a reference line for the transects cast by the DSAS software. The transects intersect each shoreline at the measurement points, which are then used to calculate shoreline-change rates for the Massachusetts Office of Coastal Zone Management Shoreline Change Project.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 2011 (process 1 of 9)
    A baseline shapefile was constructed in segments positioned either completely offshore or completely onshore from the time series of shoreline positions using standard editing tools in ArcMap v.9.3. The baseline was positioned to conform to changes in the combined orientation of the shorelines alongshore. This was done so that the transects generated by the Digital Shoreline Analysis System software from the baseline, would intersect perpendicular to the general trend of the shorelines.
    This process step and all subsequent process steps were performed by the same person - Theresa Smith. Person who carried out this activity:
    Theresa Smith
    U.S. Geological Survey
    Contractor
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 (voice)
    theresasmith@usgs.gov
    Date: 2011 (process 2 of 9)
    The Digital Shoreline Analysis System software requires that all features reside within a geodatabase. The baseline file was imported into a personal geodatabase in ArcCatalog v9.3 by right-clicking on the geodatabase > Import feature class. After transects were generated, the entire geodatabase was upgraded to v.10 by right-clicking on the geodatabase and choosing "Properties" from the pop-up window in ArcCatalog v.10. The "Upgrade Geodatabase" button was clicked at the bottom of the General tab in the Database Properties window.
    Date: 10-Oct-2012 (process 3 of 9)
    After transects were generated, it was necessary to edit sections of the baseline using the dynamic topology in DSAS that allows edits to the baseline to update the position of transects.
    Date: 16-Oct-2012 (process 4 of 9)
    For publication purposes, the baseline file was exported from a personal geodatabase in ArcCatalog v.10 by right-clicking on the geodatabase > Export feature class.
    Date: 16-Nov-2012 (process 5 of 9)
    The baseline shapefile was projected in Esri's ArcToolbox (v.10) > Data Management Tools > Projections and Transformations > Feature > Project. Parameters: input projection - NAD_1983_StatePlane_Massachusetts_Mainland_FIPS_2001; output projection - geographic coordinates (NAD83); transformation - none.
    Date: 11-Oct-2017 (process 6 of 9)
    Edits to the metadata were made to fix any errors that MP v 2.9.36 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Attempted to modify http to https where appropriate. Added a landing page link as the first link in the identification section. Fixed online link to DSAS cross-reference. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. 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
    Date: 20-Jul-2018 (process 7 of 9)
    USGS Thesaurus keywords added to the keyword section. 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
    Date: 18-Nov-2019 (process 8 of 9)
    Crossref DOI link was added as the first link in the metadata. 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
    Date: 08-Sep-2020 (process 9 of 9)
    Added keywords section with USGS persistent identifier as theme keyword. 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?
    Thieler, E.R., Smith, T.L., Knisel, Julia, and Sampson, D.W., 2013, Massachusetts Shoreline Change Mapping and Analysis Project, 2013 Update: Open-File Report 2012-1189, 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 of software at time of use was 4.3
    Thieler, E. Robert, O'Connell, James F., and Schupp, Courtney A., 20010904, The Massachusetts Shoreline Change Project: 1800s to 1994 Technical Report: U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details: Administrative Report

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

  1. How well have the observations been checked?
    The attributes for these baseline data 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?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This baseline file is complete and contains all segments used to calculate shoreline change rates along sections of the Massachusetts Nantucket coastal region where shoreline position data were available.
  5. How consistent are the relationships among the observations, including topology?
    The baseline segments here were used to generate transects for shoreline change rate calculations using the Digital Shoreline Analysis System software. They do not overlap and are not necessarily continuous.

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 from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management as the originators of this dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-457-2350 (voice)
    508-457-2310 (FAX)
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, 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 information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials.
    Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: This WinZip (version 16.5) file contains a shapefile which includes the baseline for generating shore-normal transects in DSAS. The metadata is also included. in format Shapefile (version ArcGIS 10) Esri polyline shapefile Size: 1
      Network links: https://pubs.usgs.gov/of/2012/1183/data/Nantucket/Nantucket_baseline.zip
    • Cost to order the data: None

  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: 16-Nov-2021
Metadata author:
Theresa L. Smith
U.S. Geological Survey
Contractor Geologist
384 Woods Hole Road
Woods Hole, MA
USA

508-548-8700 (voice)
508-457-2310 (FAX)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the metadata contact is no longer with the USGS or the email is otherwise invalid.
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2012-1183/Nantucket_baseline.shp.xml.faq.html>
Generated by mp version 2.9.50 on Tue Nov 16 10:06:49 2021