Intersects for coastal region of Nantucket, Massachusetts, generated to calculate shoreline change rates using the Digital Shoreline Analysis System version 5.1

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What does this data set describe?

Title:
Intersects for coastal region of Nantucket, Massachusetts, generated to calculate shoreline change rates using the Digital Shoreline Analysis System version 5.1
Abstract:
The Massachusetts Office of Coastal Zone Management launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast and support local land-use decisions. Trends of shoreline position over long and short-term timescales provide information to landowners, managers, and potential buyers about possible future impacts to coastal resources and infrastructure. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates along ocean-facing sections of the Massachusetts coast. In 2013 two oceanfront shorelines for Massachusetts were added using 2008-2009 color aerial orthoimagery and 2007 topographic lidar datasets obtained from NOAA's Ocean Service, Coastal Services Center. In 2018, two new mean high water (MHW) shorelines for the Massachusetts coast extracted from lidar data between 2010-2014 were added to the dataset. This 2021 data release includes rates that incorporate one new shoreline from lidar data extracted in 2018 by the U.S. Army Corps of Engineers (USACE) Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX), added to the existing database of all historical shorelines (1844-2014), for the North Shore, South Shore, Cape Cod Bay, Outer Cape, Buzzard’s Bay, South Cape, Nantucket, and Martha’s Vineyard. 2018 lidar data did not cover the Boston or Elizabeth Islands regions. Included in this data release is a proxy-datum bias reference line that accounts for the positional difference in a proxy shoreline (the high water Line shoreline) and a datum shoreline (the mean high water shoreline. This issue is explained further in Ruggiero and List (2009) and in the process steps of the metadata associated with the rates. This release includes both long-term (~150+ years) and short term (~30 years) rates. Files associated with the long-term rates have “LT” in their names, files associated with short-term rates have "ST” in their names.
  1. How might this data set be cited?
    U.S. Geological Survey, 20210831, Intersects for coastal region of Nantucket, Massachusetts, generated to calculate shoreline change rates using the Digital Shoreline Analysis System version 5.1: data release doi:10.5066/P9YGIYFX, 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.

    Bartlett, Marie K., Henderson, Rachel E., Farris, Amy S., and Himmelstoss, Emily A., 2021, Massachusetts Shoreline Change Project, 2021 Update: A GIS Compilation of Shoreline Change Rates Calculated Using Digital Shoreline Analysis System Version 5.1, With Supplementary Intersects and Baselines for Massachusetts: data release doi:10.5066/P9YGIYFX, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    suggested citation: Bartlett, M.K., Henderson, R. E., Farris, A.S., and Himmelstoss, E.A., 2021, Massachusetts shoreline change project, 2021 update–A GIS compilation of shoreline change rates calculated using Digital Shoreline Analysis System version 5.1, with supplementary intersects and baselines for Massachusetts: U.S. Geological Survey data release. https://doi.org/10.5066/P9YGIYFX
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.3193
    East_Bounding_Coordinate: -69.9592
    North_Bounding_Coordinate: 41.3873
    South_Bounding_Coordinate: 41.2374
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/6108308dd34ef8d70565bd53?name=Nantucket_intersects_browse.PNG (png)
    Map view of data
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2021
    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
    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 0.0197425946. Longitudes are given to the nearest 0.0261674174. Latitude and longitude values are specified in Decimal seconds. The horizontal datum used is WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
  7. How does the data set describe geographic features?
    NantucketN_intersects_LT.shp
    The intersection points are generated by DSAS where each DSAS generated transect crosses a shoreline. These intersections represent the shoreline position, and contain the data necessary for DSAS to compute long-term rates, with and without the proxy-datum bias. Point Object Count: 8624 (Source: USGS)
    FID
    Internal feature number used as a unique identifier of an object within a table primarily used in shapefiles. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    The geometry field (shape) is automatically created and maintained by ArcGIS. It provides a definition of the feature type (point, line, polygon). (Source: ESRI) Coordinates defining the features.
    TransectID
    The TransectID relates directly to the original transect file Object Identifier, ObjectID or OID (Source: USGS)
    Range of values
    Minimum:1
    Maximum:unlimited
    TransOrder
    Assigned by DSAS based on ordering of transects along the baseline. Used to allow user to sort transect data along the baseline from baseline start to baseline end. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    BaselineID
    Values in this field correlate to the baseline attribute field ID and are assigned by DSAS to identify the baseline segment used to generate the measurement transect. Baseline segments assigned an ID = 0 are ignored by DSAS and no transects will be cast along those line segments. (Source: USGS)
    Range of values
    Minimum:1
    Maximum:unlimited
    ShorelineI
    Date of shoreline position; date of survey as determined from shoreline layer. (Source: USGS) Date of the shoreline in mm/dd/yyyy
    Distance
    The distance in meters between the DSAS reference baseline and the shoreline intersection point along a DSAS transect. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin.
    IntersectX
    The X-coordinate location in eastings of the intersect point in WGS84 UTM19N. (Source: USGS)
    Range of values
    Minimum:389613.315173
    Maximum:416575.523026
    IntersectY
    The Y-coordinate location in northings of the intersect point in WGS84 UTM19N. (Source: USGS)
    Range of values
    Minimum:4569871.586360
    Maximum:4582287.530220
    Uncertaint
    The uncertainty of the shoreline intersect point as defined by the positional-uncertainty value (DSAS_uncy) of the shoreline (ShorelineID). (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    Bias_Dista
    The distance in meters between the DSAS reference baseline and the shoreline intersection point along a DSAS transect with the proxy-datum bias applied. May be positive or negative depending on the orientation of the baseline. (Source: USGS)
    Range of values
    Minimum:-366.767791
    Maximum:770.797716
    BIAS
    The estimated unidirectional horizontal offset between the MHW elevation of the lidar data and the HWL shoreline position. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    BIAS_X
    The X-coordinate location of the intersect point with the bias applied. (Source: USGS)
    Range of values
    Minimum:389613.314204
    Maximum:416575.522026
    BIAS_Y
    The Y-coordinate location of the intersect point with the bias applied. (Source: USGS)
    Range of values
    Minimum:4569871.587320
    Maximum:4582287.529650
    Bias_Uncer
    This is an estimate of the uncertainty of the bias corrected shoreline. It is the shoreline uncertainty and the bias uncertainty added in quadrature (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    NantucketN_intersects_ST.shp
    The intersection points are generated by DSAS where each DSAS generated transect crosses a shoreline. These intersections represent the shoreline position, and contain the data necessary for DSAS to compute short-term rates, with and without the proxy-datum bias. Point Object Count: 5253 (Source: USGS)
    FID
    Internal feature number used as a unique identifier of an object within a table primarily used in shapefiles. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    The geometry field (shape) is automatically created and maintained by ArcGIS. It provides a definition of the feature type (point, line, polygon). (Source: ESRI) Coordinates defining the features.
    TransectID
    The TransectID relates directly to the original transect file Object Identifier, ObjectID or OID (Source: USGS)
    Range of values
    Minimum:1
    Maximum:unlimited
    TransOrder
    Assigned by DSAS based on ordering of transects along the baseline. Used to allow user to sort transect data along the baseline from baseline start to baseline end. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    BaselineID
    Values in this field correlate to the baseline attribute field ID and are assigned by DSAS to identify the baseline segment used to generate the measurement transect. Baseline segments assigned an ID = 0 are ignored by DSAS and no transects will be cast along those line segments. (Source: USGS)
    Range of values
    Minimum:1
    Maximum:unlimited
    ShorelineI
    Date of shoreline position; date of survey as determined from shoreline layer. (Source: USGS) Date of the shoreline in mm/dd/yyyy
    Distance
    The distance in meters between the DSAS reference baseline and the shoreline intersection point along a DSAS transect. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin.
    IntersectX
    The X-coordinate location in eastings of the intersect point in WGS84 UTM19N. (Source: USGS)
    Range of values
    Minimum:390324.256875
    Maximum:416455.995027
    IntersectY
    The Y-coordinate location in northings of the intersect point in WGS84 UTM19N. (Source: USGS)
    Range of values
    Minimum:4569927.717940
    Maximum:4582770.774950
    Uncertaint
    The uncertainty of the shoreline intersect point as defined by the positional-uncertainty value (DSAS_uncy) of the shoreline (ShorelineID). (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    Bias_Dista
    The distance in meters between the DSAS reference baseline and the shoreline intersection point along a DSAS transect with the proxy-datum bias applied. May be positive or negative depending on the orientation of the baseline. (Source: USGS)
    Range of values
    Minimum:-241.937383
    Maximum:500.466767
    BIAS
    The estimated unidirectional horizontal offset between the MHW elevation of the lidar data and the HWL shoreline position. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    BIAS_X
    The X-coordinate location of the intersect point with the bias applied. (Source: USGS)
    Range of values
    Minimum:390324.256036
    Maximum:416455.994028
    BIAS_Y
    The Y-coordinate location of the intersect point with the bias applied. (Source: USGS)
    Range of values
    Minimum:4569927.718920
    Maximum:4582770.774860
    Bias_Uncer
    This is an estimate of the uncertainty of the bias corrected shoreline. It is the shoreline uncertainty and the bias uncertainty added in quadrature. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    NantucketS_intersects_LT.shp
    The intersection points are generated by DSAS where each DSAS generated transect crosses a shoreline. These intersections represent the shoreline position, and contain the data necessary for DSAS to compute long-term rates, with and without the proxy-datum bias. Point Object Count: 8900 (Source: USGS)
    FID
    Internal feature number used as a unique identifier of an object within a table primarily used in shapefiles. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    The geometry field (shape) is automatically created and maintained by ArcGIS. It provides a definition of the feature type (point, line, polygon). (Source: ESRI) Coordinates defining the features.
    TransectID
    The TransectID relates directly to the original transect file Object Identifier, ObjectID or OID (Source: USGS)
    Range of values
    Minimum:1
    Maximum:unlimited
    TransOrder
    Assigned by DSAS based on ordering of transects along the baseline. Used to allow user to sort transect data along the baseline from baseline start to baseline end. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    BaselineID
    Values in this field correlate to the baseline attribute field ID and are assigned by DSAS to identify the baseline segment used to generate the measurement transect. Baseline segments assigned an ID = 0 are ignored by DSAS and no transects will be cast along those line segments. (Source: USGS)
    Range of values
    Minimum:1
    Maximum:unlimited
    ShorelineI
    Date of shoreline position; date of survey as determined from shoreline layer. (Source: USGS) Date of the shoreline in mm/dd/yyyy
    Distance
    The distance in meters between the DSAS reference baseline and the shoreline intersection point along a DSAS transect. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin.
    IntersectX
    The X-coordinate location in eastings of the intersect point in WGS84 UTM19N. (Source: USGS)
    Range of values
    Minimum:391927.323340
    Maximum:419661.564240
    IntersectY
    The Y-coordinate location in northings of the intersect point in WGS84 UTM19N. (Source: USGS)
    Range of values
    Minimum:4565606.338520
    Maximum:4582993.106180
    Uncertaint
    The uncertainty of the shoreline intersect point as defined by the positional-uncertainty value (DSAS_uncy) of the shoreline (ShorelineID). (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    Bias_Dista
    The distance in meters between the DSAS reference baseline and the shoreline intersection point along a DSAS transect with the proxy-datum bias applied. May be positive or negative depending on the orientation of the baseline. (Source: USGS)
    Range of values
    Minimum:-867.183515
    Maximum:598.233840
    BIAS
    The estimated unidirectional horizontal offset between the MHW elevation of the lidar data and the HWL shoreline position. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    BIAS_X
    The X-coordinate location of the intersect point with the bias applied. (Source: USGS)
    Range of values
    Minimum:391919.795010
    Maximum:419671.276716
    BIAS_Y
    The Y-coordinate location of the intersect point with the bias applied. (Source: USGS)
    Range of values
    Minimum:4565596.959460
    Maximum:4583001.208540
    Bias_Uncer
    This is an estimate of the uncertainty of the bias corrected shoreline. It is the shoreline uncertainty and the bias uncertainty added in quadrature (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    NantucketS_intersects_ST.shp
    The intersection points are generated by DSAS where each DSAS generated transect crosses a shoreline. These intersections represent the shoreline position, and contain the data necessary for DSAS to compute short-term rates, with and without the proxy-datum bias. Point Object Count: 6334 (Source: USGS)
    FID
    Internal feature number used as a unique identifier of an object within a table primarily used in shapefiles. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    The geometry field (shape) is automatically created and maintained by ArcGIS. It provides a definition of the feature type (point, line, polygon). (Source: ESRI) Coordinates defining the features.
    TransectID
    The TransectID relates directly to the original transect file Object Identifier, ObjectID or OID (Source: USGS)
    Range of values
    Minimum:1
    Maximum:unlimited
    TransOrder
    Assigned by DSAS based on ordering of transects along the baseline. Used to allow user to sort transect data along the baseline from baseline start to baseline end. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    BaselineID
    Values in this field correlate to the baseline attribute field ID and are assigned by DSAS to identify the baseline segment used to generate the measurement transect. Baseline segments assigned an ID = 0 are ignored by DSAS and no transects will be cast along those line segments. (Source: USGS)
    Range of values
    Minimum:1
    Maximum:unlimited
    ShorelineI
    Date of shoreline position; date of survey as determined from shoreline layer. (Source: USGS) Date of the shoreline in mm/dd/yyyy
    Distance
    The distance in meters between the DSAS reference baseline and the shoreline intersection point along a DSAS transect. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin.
    IntersectX
    The X-coordinate location in eastings of the intersect point in WGS84 UTM19N. (Source: USGS)
    Range of values
    Minimum:392834.500186
    Maximum:419625.864793
    IntersectY
    The Y-coordinate location in northings of the intersect point in WGS84 UTM19N. (Source: USGS)
    Range of values
    Minimum:4565729.042400
    Maximum:4582886.785340
    Uncertaint
    The uncertainty of the shoreline intersect point as defined by the positional-uncertainty value (DSAS_uncy) of the shoreline (ShorelineID). (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    Bias_Dista
    The distance in meters between the DSAS reference baseline and the shoreline intersection point along a DSAS transect with the proxy-datum bias applied. May be positive or negative depending on the orientation of the baseline. (Source: USGS)
    Range of values
    Minimum:-876.788089
    Maximum:100.433676
    BIAS
    The estimated unidirectional horizontal offset between the MHW elevation of the lidar data and the HWL shoreline position. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    BIAS_X
    The X-coordinate location of the intersect point with the bias applied. (Source: USGS)
    Range of values
    Minimum:392826.971857
    Maximum:419635.588273
    BIAS_Y
    The Y-coordinate location of the intersect point with the bias applied. (Source: USGS)
    Range of values
    Minimum:4565719.648470
    Maximum:4582894.887690
    Bias_Uncer
    This is an estimate of the uncertainty of the bias corrected shoreline. It is the shoreline uncertainty and the bias uncertainty added in quadrature (Source: USGS)
    Range of values
    Minimum:0
    Maximum:unlimited
    Entity_and_Attribute_Overview:
    The entity and attribute information provided here describes the tabular data associated with the intersects needed to calculate long-term (greater than 50 years, and typically closer to 100 years) and short-term (approximately 30 years) shoreline change rates. Please review the individual attribute descriptions for detailed information. All calculations for length are in meter units and were based on the UTM zone 19N WGS 84 projection. This region has two shapefiles describing intersects, long-term and short-term.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey-ScienceBase

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: Marie K. Bartlett
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 x 2306 (voice)
    508-457-2310 (FAX)
    mbartlett@usgs.gov

Why was the data set created?

This dataset consists of point data which are created by the Digital Shoreline Analysis System (DSAS) version v5.1 at the intersection of shoreline and transect locations. Rate calculations were computed within a GIS using the Digital Shoreline Analysis System (DSAS) version 5.1, an ArcGIS extension developed by the U.S. Geological Survey. Measurement transects are cast by DSAS from the baseline to intersect shoreline vectors, and the intersect data provide location and time information used to calculate rates of change. These point data contain identification information related to the DSAS transect (TransectID, TransOrder) as well as the shoreline (ShorelineID, Uncertainty) and proxy-datum bias data (if applicable).

How was the data set created?

  1. From what previous works were the data drawn?
    MA 1844 - 2018 Shorelines (source 1 of 3)
    Bartlett, Marie K., Farris, Amy S., Weber, Kathryn M., and Himmelstoss, Emily A., 2021, Massachusetts Shoreline Change Project: A GIS Compilation of Vector Shorelines (1844-2018): data release doi:10.5066/P9O8QA8N, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Bartlett, M.K., Farris, A.S., and Weber, K.M., Himmelstoss, E.A., 2021, Massachusetts shoreline change project—A GIS compilation of vector shorelines (1844-2018): U.S. Geological Survey data release
    Type_of_Source_Media: vector digital data
    Source_Contribution:
    Shorelines published as part of the Massachusetts Shoreline Change Project, 2021 Update were compiled for shoreline change analysis with DSAS v5.1
    NantucketN_baseline (source 2 of 3)
    Bartlett, Marie K., Henderson, Rachel E., Farris, Amy S., and Himmelstoss, Emily A., 2021, Baseline for the northern coast of Nantucket, Massachusetts, generated to calculate shoreline change rates using the Digital Shoreline Analysis System version 5.1: data release product doi:10.5066/P9YGIYFX, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: vector digital data
    Source_Contribution:
    Baseline files for region published as part of the Massachusetts Shoreline Change Project, 2021 Update used for shoreline change analysis with DSAS v5.1
    NantucketS_baseline (source 3 of 3)
    Bartlett, Marie K., Henderson, Rachel E., Farris, Amy S., and Himmelstoss, Emily A., 2021, Baseline for the southern coast of Nantucket, Massachusetts, generated to calculate shoreline change rates using the Digital Shoreline Analysis System version 5.1: data release product doi:10.5066/P9YGIYFX, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: vector digital data
    Source_Contribution:
    Baseline files for region published as part of the Massachusetts Shoreline Change Project, 2021 Update used for shoreline change analysis with DSAS v5.1
  2. How were the data generated, processed, and modified?
    Date: 2020 (process 1 of 11)
    Explanation of the methods used to calculate shoreline change rates as part of the 2021 update for the Massachusetts Office of Coastal Zone Management Shoreline Change Project: This data release consists of intersect point shapefiles that hold the data necessary to calculate long- and short-term rates of shoreline change. Depending on the available data, the shorelines used for analysis may include those referenced to mean high water (MHW) or a proxy-based high water line (HWL).Transects with both MHW and HWL shorelines will have the proxy-datum bias applied. Shoreline data from the 2021 data release (historical and 2018), were merged into a single feature class (MA_shorelines_LT) for the long-term shoreline change. For this completed shoreline compilation, shoreline data were extracted for the last 30 years and merged into a feature class (MA_shorelines_ST) to calculate short-term shoreline change. All files were projected to UTM zone 19N coordinates and confirmed to have the same attribute names needed for use in DSAS. Note the range of shoreline dates will vary by location. Please check the intersect file attributes for a record of the exact dates used. This process step and all subsequent process steps were performed by the same person: Marie K. Bartlett Person who carried out this activity:
    Marie K. Bartlett
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 x2306 (voice)
    mbartlett@usgs.gov
    Data sources used in this process:
    • MA 1844 - 2018 Shorelines
    Data sources produced in this process:
    • MA_shorelines_LT
    • MA_shorelines_ST
    Date: 2020 (process 2 of 11)
    Transect features generated in a personal geodatabase using DSAS v5.1.2020.0720.0030. Parameters Used: baseline layer= NantucketN_baseline, baseline group field=DSAS_group, transect spacing=50 meters, search distance=200 meters, land direction=right, shoreline intersection=seaward, File produced = NantucketN_trans_LT. For additional details on these parameters, please see the DSAS help file distributed with the DSAS software, or visit the USGS website at: https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas. Some transects were manually edited for length, moved, or deleted in an edit session using standard editing tools in ArcMap v10.7.1 Data sources used in this process:
    • MA_shorelines_LT
    • NantucketN_baseline
    Data sources produced in this process:
    • NantucketN_transects_LT
    Date: 2021 (process 3 of 11)
    Shoreline intersects and rate calculations performed for long-term rates with and without bias. Parameters Used: shoreline layer= MA_shorelines_LT, shoreline date field=Date_, shoreline uncertainty field name=Uncy, the default accuracy=10 meters, shoreline intersection=seaward, stats calculations=[SCE, NSM, LRR], shoreline threshold=3, confidence interval=90%. Files produced = NantucketN_trans_LT_rates_20210621_153805, NantucketN_trans_LT_intersect_20210621_153805. NOTE: All shorelines have an uncertainty value listed in the attribute table that provides the horizontal uncertainty associated with the shoreline, regardless of the method used. The shoreline database contains both MHW and HWL shorelines. Therefore, a proxy-datum bias (PDB), stored as a line feature class appended to the reference baseline, is applied during rate calculation. For more information about the origin of the proxy-datum bias, see Ruggiero and List (2009). Rate statistics are presented with both the PDB applied, and with the bias omitted, in which case the attribute field will show “NB_” or “No bias”. The bias uncertainty values are stored within the bias feature attribute table. Data sources used in this process:
    • MA_shorelines_LT
    • NantucketN_transects_LT
    Data sources produced in this process:
    • NantucketN_trans_rates_LT
    • NantucketN_intersects_LT
    Date: 2021 (process 4 of 11)
    Transect features generated in a personal geodatabase using DSAS v5.1.2020.0720.0030. Parameters Used: baseline layer= NantucketN_baseline, baseline group field=DSAS_group, transect spacing=50 meters, search distance=200 meters, land direction=right, shoreline intersection=seaward, File produced = NantucketN_trans_ST. For additional details on these parameters, please see the DSAS help file distributed with the DSAS software, or visit the USGS website at: https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas Some transects were manually edited for length, moved, or deleted in an edit session using standard editing tools in ArcMap v10.7.1. Data sources used in this process:
    • MA_shorelines_ST
    • NantucketN_baseline
    Data sources produced in this process:
    • NantucketN_transects_ST
    Date: 2021 (process 5 of 11)
    Shoreline intersects and rate calculations performed for long-term rates with and without bias. Parameters Used: shoreline layer= MA_shorelines_ST, shoreline date field=Date_, shoreline uncertainty field name=Uncy, the default accuracy=5.1 meters, shoreline intersection=seaward, stats calculations=[SCE, NSM, EPR LRR], shoreline threshold=2, confidence interval=90%. Files produced = NantucketN_trans_ST_rates_20210621_163023, NantucketN_trans_ST_intersect_20210621_163023. NOTE: All shorelines have an uncertainty value listed in the attribute table that provides the horizontal uncertainty associated with the shoreline, regardless of the method used. The shoreline database contains both MHW and HWL shorelines thus a proxy-datum bias (PDB), stored as a line feature class appended to the reference baseline, is applied during rate calculation. For more information about the origin of the proxy-datum bias, see Ruggiero and List (2009). Rate statistics are presented with both the PDB applied, and with the bias omitted, in which case the attribute field will show “NB_” or “No bias”. The bias uncertainty values are stored within the bias feature attribute table. Data sources used in this process:
    • MA_shorelines_ST
    • NantucketN_transects_ST
    Data sources produced in this process:
    • NantucketN_trans_rates_ST
    • NantucketN_intersects_ST
    Date: 2021 (process 6 of 11)
    Transect features generated in a personal geodatabase using DSAS v5.1.2020.0720.0030. Parameters Used: baseline layer= NantucketS_baseline, baseline group field=DSAS_group, transect spacing=50 meters, search distance=200 meters, land direction=left, shoreline intersection=seaward, File produced = NantucketS_trans_LT. For additional details on these parameters, please see the DSAS help file distributed with the DSAS software, or visit the USGS website at: https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas Some transects were manually edited for length, moved, or deleted in an edit session using standard editing tools in ArcMap v10.7.1. Data sources used in this process:
    • MA_shorelines_ST
    • NantucketS_baseline
    Data sources produced in this process:
    • NantucketS_transects_LT
    Date: 2021 (process 7 of 11)
    Shoreline intersects and rate calculations performed for long-term rates with and without bias. Parameters Used: shoreline layer= MA_shorelines_LT, shoreline date field=Date_, shoreline uncertainty field name=Uncy, the default accuracy=10 meters, shoreline intersection=seaward, stats calculations=[SCE, NSM, LRR], shoreline threshold=3, confidence interval=90%. Files produced = NantucketS_trans_LT_rates_20210706_144229, NantucketS_LT_intersect_20210706_144229. NOTE: All shorelines have an uncertainty value listed in the attribute table that provides the horizontal uncertainty associated with the shoreline, regardless of the method used. The shoreline database contains both MHW and HWL shorelines thus a proxy-datum bias (PDB), stored as a line feature class appended to the reference baseline, is applied during rate calculation. For more information about the origin of the proxy-datum bias, see Ruggiero and List (2009). Rate statistics are presented with both the PDB applied, and with the bias omitted, in which case the attribute field will show “NB_” or “No bias”. The bias uncertainty values are stored within the bias feature attribute table. Data sources used in this process:
    • MA_shorelines_LT
    • NantucketS_transects_LT
    Data sources produced in this process:
    • NantucketS_trans_rates_LT
    • NantucketS_intersects_LT
    Date: 2021 (process 8 of 11)
    Transect features generated in a personal geodatabase using DSAS v5.1.2020.0720.0030. Parameters Used: baseline layer= NantucketS_baseline, baseline group field=DSAS_group, transect spacing=50 meters, search distance=200 meters, land direction=left, shoreline intersection=seaward, File produced = NantucketS_trans_ST. For additional details on these parameters, please see the DSAS help file distributed with the DSAS software, or visit the USGS website at: https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas Some transects were manually edited for length, moved, or deleted in an edit session using standard editing tools in ArcMap v10.7.1. Data sources used in this process:
    • MA_shorelines_ST
    • NantucketS_baseline
    Data sources produced in this process:
    • NantucketS_transects_ST
    Date: 2021 (process 9 of 11)
    Shoreline intersects and rate calculations performed for long-term rates with and without bias. Parameters Used: shoreline layer= MA_shorelines_ST, shoreline date field=Date_, shoreline uncertainty field name=Uncy, the default accuracy=5.1 meters, shoreline intersection=seaward, stats calculations=[SCE, NSM, EPR LRR], shoreline threshold=2, confidence interval=90%. Files produced = NantucketS_trans_ST_rates_20210308_121152, NantucketS_trans_ST_intersect_20210308_121152. NOTE: All shorelines have an uncertainty value listed in the attribute table that provides the horizontal uncertainty associated with the shoreline, regardless of the method used. The shoreline database contains both MHW and HWL shorelines thus a proxy-datum bias (PDB), stored as a line feature class appended to the reference baseline, is applied during rate calculation. For more information about the origin of the proxy-datum bias, see Ruggiero and List (2009). Rate statistics are presented with both the PDB applied, and with the bias omitted, in which case the attribute field will show “NB_” or “No bias”. The bias uncertainty values are stored within the bias feature attribute table. Data sources used in this process:
    • MA_shorelines_ST
    • NantucketS_transects_ST
    Data sources produced in this process:
    • NantucketS_trans_rates_ST
    • NantucketS_intersects_ST
    Date: 2021 (process 10 of 11)
    The intersect feature classes were exported to shapefiles in ArcMap v10.7.1 by right-clicking the transect layer > Data > Export data.
    Date: 2021 (process 11 of 11)
    The exported intersect shapefiles were projected in Esri's ArcToolbox (v10.7.1) > Data Management Tools > Projections and Transformations > Project. Parameters: input projection = UTM zone 19N (WGS84); output projection = geographic coordinates (WGS84); transformation = none. Data sources used in this process:
    • NantucketN_intersects_LT
    • NantucketN_intersects_ST
    • NantucketS_intersects_LT
    • NantucketS_intersects_ST
    Data sources produced in this process:
    • NantucketN_intersects_LT
    • NantucketN_intersects_ST
    • NantucketS_intersects_LT
    • NantucketS_intersects_ST
  3. What similar or related data should the user be aware of?
    Himmelstoss, Emily A., Farris, Amy S., Henderson, Rachel E., Kratzmann, Meredith G., Ergul, Ayhan, Zhang, Ouya, and Zichichi, Jessica L., 2018, Digital Shoreline Analysis System (version 5.0): U.S. Geological Survey Software: software release version 5.0, U.S. Geological Survey, Reston, VA.

    Online Links:

    Himmelstoss, Emily A., Henderson, Rachel E., Kratzmann, Meredith G., and Farris, Amy S., 2018, DSAS v5.0 user guide: Open-File Report 2018-1179, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Himmelstoss, E.A., Henderson, R.E., Kratzmann, M, Farris, A., 2018, DSAS version 5.0 user guide. U.S. Geological Survey report 2018-1179, https://doi.org/10.3133/ofr20181179
    Himmelstoss, Emily A., Farris, Amy S., and Weber, Kathryn M., 2018, Massachusetts Shoreline Change Project: A GIS Compilation of Vector Shorelines for the 2018 update: data release DOI:10.5066/P9O7S72B, U.S. Geological Survey, Coastal and Marine Geology Program, Reston, VA.

    Online Links:

    Ruggiero, Peter, and List, Jeffrey H., 200909, Improving Accuracy and Statistical Reliability of Shoreline Position and Change Rate Estimates: Journal of Coastal Research vol. 255, Coastal Education and Research Foundation, n/a.

    Online Links:

    Other_Citation_Details: ppg. 1069-1081
    Himmelstoss, Emily A., Farris, Amy S., and Weber, Kathryn M., 2019, Massachusetts Shoreline Change Project, 2018 Update: A GIS Compilation of Shoreline Change Rates Calculated Using Digital Shoreline Analysis System Version 5.0, With Supplementary Intersects and Baselines for Massachusetts: Data release DOI:10.5066/P9RRBEYK, U.S. Geological Survey, Reston, VA.

    Online Links:


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

  1. How well have the observations been checked?
    The attributes of this dataset are based on the field requirements of the Digital Shoreline Analysis System and were automatically generated by the software during the generation of the intersects layer.
  2. How accurate are the geographic locations?
    The intersection points represent the location where transects cast by the Digital Shoreline Analysis System (DSAS) software crosses a historical shoreline position. They can be used to visually display which shorelines were used in the rate calculations and capture details on the shoreline represented by the intersection. The distances between the reference baseline and each shoreline intersection along a transect are used by the DSAS software to compute the shoreline change metrics. The positional uncertainties associated with the shoreline and intersection points are captured in the shoreline attribute table.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This dataset contains all the shoreline/transect intersects used to compute rates in the DSAS v5.1 software application.
  5. How consistent are the relationships among the observations, including topology?
    These data were generated using DSAS, an automated software program, which does not perform checks for fidelity of the input features. Following generation of the rates and intersects by the DSAS software a visual inspection of the intersects was performed in map view to determine that no unwanted measurements were included in the desired (long- or short-term) shoreline change analysis.

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 These data were automatically generated using the DSAS v5.1 software application. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset. These data are not to be used for navigation.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - GS ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    United States

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? The dataset contains the point intersections used for the analysis of shoreline data, (SHP and other shapefile components), browse graphic, and the FGDC CSDGM metadata in XML format.
  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. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), and have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. 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?
  5. What hardware or software do I need in order to use the data set?
    These data are available in a point shapefile format. The user must have software to read and process the data components of a shapefile.

Who wrote the metadata?

Dates:
Last modified: 19-Mar-2024
Metadata author:
Marie K. Bartlett
U.S. Geological Survey
384 Woods Hole Road
Woods Hole, MA
USA

508-548-8700 x2306 (voice)
508-547-2310 (FAX)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the person is no longer with USGS. (updated on 20240319)
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

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