Digital Shoreline Analysis System (DSAS) version 5.0 transects with shoreline rate change calculations at Barter Island Alaska, 1947 to 2020

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Gibbs, Ann E., 20201204, Digital Shoreline Analysis System (DSAS) version 5.0 transects with shoreline rate change calculations at Barter Island Alaska, 1947 to 2020: data release DOI: 10.5066/P9CRBC5I, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P9CRBC5I
   • https://www.sciencebase.gov/catalog/item/5fb716ded34eb413d5e143dd

   This is part of the following larger work.
   Gibbs, Ann E., Jones, Benjamin M., and Richmond, Bruce M., 2020, A GIS compilation of vector shorelines and coastal bluff edge positions, and associated rate-of-change data for Barter Island, Alaska: data release DOI:10.5066/P9CRBC5I, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P9CRBC5I

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -143.707127369
   East_Bounding_Coordinate: -143.621379794
   North_Bounding_Coordinate: 70.136186014
   South_Bounding_Coordinate: 70.131006408
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 29-Jul-1947

   Ending_Date: 10-Jul-2020

   Currentness_Reference:

   ground condition.

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polyline)
   

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 (1902)
   2. What coordinate system is used to represent geographic features?
      

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:

      UTM_Zone_Number: 7
      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -141.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in Meter
      The horizontal datum used is D_North_American_1983.
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
      
7. How does the data set describe geographic features?

   Attribute Table

   Table containing attribute information associated with the data set. (Source: Producer defined)

   FID

   The object identification field is automatically created and maintained by ArcGIS. It establishes a unique ID for each row in the attribute table. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0
   Maximum:	1901

   Shape

   The geometry field is automatically created and maintained by ArcGIS. It provides a definition of the feature type (point, line, polygon). (Source: Himmelstoss and others (2018))

   Value	Definition
   Polyline	ESRI polyline shapefile

   TransectID

   A permanent and unique identification number for each transect in the output rates table calculated by DSAS. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	1
   Maximum:	1914

   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: Himmelstoss and others (2018))

   Range of values
   Minimum:	1
   Maximum:	4

   GroupID

   Values in this field correlate to the optional baseline attribute field “DSAS_group” (Group_) and are assigned by DSAS if selected by user. This field is used to aggregate sections of the coast into groups. All transects within a group will have average summary statistics in the DSAS summary report. Refer to the baseline field requirements in section 5.3.3 and a description of the summary report in section 9 for more information. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	1
   Maximum:	4

   TransOrder

   Assigned by DSAS on the basis of transect order along the baseline or baselines. If the user manually adds transects to the file in an edit session, they will be added to the end of the transect attribute table and given a new TransID (ObjectID). However, TransOrder will be updated to reflect the position of the new transect with respect to the other transects along the baseline. This field provides the user with a method to sort transect attribute data from the start of the baseline segment with an ID=1 and increment by one alongshore to the end of the final baseline segment. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	2
   Maximum:	1915

   Azimuth

   Used to record the azimuth of the transect measured in degrees clockwise from north. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	112.56
   Maximum:	204.44

   ShrCount

   The total number of shorelines intersected by the transect and used for change analysis. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0
   Maximum:	6

   TCD

   The “total cumulative distance” (TCD) is the measure (in meters) along shore from the start of the baseline segment with an ID=1 and measured sequentially alongshore to the end of the final baseline segment. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	10
   Maximum:	37955.32
   Units:	Meters

   SHAPE_Leng

   Length of transect in meter units, assuming data were properly projected in a meter-based coordinate system. This field is automatically generated and maintained when data are within a geodatabase. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	230.18
   Maximum:	1500

   SCE

   The shoreline change envelope (SCE) reports a distance, not a rate. The SCE is the distance between the shoreline farthest from and closest to the baseline at each transect. This represents the total change in shoreline movement for all available shoreline positions and is not related to their dates. (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	1.55
   Maximum:	886.98
   Units:	Meters

   NSM

   The net shoreline movement (NSM) reports the distance between the oldest and youngest shorelines for each transect. This represents the total distance between the oldest and youngest shorelines. If this distance is divided by the number of years elapsed between the two shoreline positions, the result is the End Point Rate (EPR). (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	-471.73
   Maximum:	872.44
   Units:	Meters

   EPR

   End-point rate (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	-6.47
   Maximum:	11.96

   EPRunc

   Uncertainty of the end point rate (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0.23
   Maximum:	0.23

   LRR

   Linear regression rate (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	-6.28
   Maximum:	11.9
   Units:	Meters/year

   LR2

   R-squared of linear regression (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0
   Maximum:	0.98

   LSE

   Standard error of linear regression (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0.61
   Maximum:	174.57

   LCI90

   90% confidence interval of linear regression (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0.02
   Maximum:	5.95

   WLR

   Weighted linear regression rate (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	-7.73
   Maximum:	13.13

   WR2

   R-squared of weighted linear regression (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0
   Maximum:	0.98

   WSE

   Standard error of weighted linear regression (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0.11
   Maximum:	27.24

   WCI90

   90% confidence interval of weighted linear regression (Source: Himmelstoss and others (2018))

   Range of values
   Minimum:	0.03
   Maximum:	8.09

   Calc_Yrs

   This field indicates the DATE_ of shorelines lines used in the rate-calculation analysis. (Source: Producer defined) Multiple unique values

   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)
   • Ann E. Gibbs
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov

Why was the data set created?

These data are part of a series of data quantifying rates and patterns of shoreline change and coastal permafrost bluff retreat from 1947 to 2020 at Barter Island. Alaska.

How was the data set created?

1. From what previous works were the data drawn?

   DSAS baseline (source 1 of 2)

   Gibbs, Ann E., 2020, Offshore baseline generated to calculate shoreline change rates at Barter Island, Alaska: U.S. Geological Survey, online.

   Online Links:

   • https://doi.org/10.5066/P9CRBC5I

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution: DSAS baseline used for calculation of shoreline change rates.
   

   Historical shoreline positions (source 2 of 2)

   Gibbs, Ann E., 2020, Historical shoreline positions at Barter Island, Alaska for the years spanning 1947 to 2020: U.S. Geological Survey, online.

   Online Links:

   • https://doi.org/10.5066/P9CRBC5I

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution:

   Historical shoreline positions were used to calculate rate-of-change statistics.

2. How were the data generated, processed, and modified?

   Date: 2020 (process 1 of 3)

   Transect features were generated using DSAS v5.0in ArcMap v10.7. Parameters Used: baseline, transect spacing=10 meters, transect length=variable 500-1500 m, cast direction=onshore, baseline location=offshore, cast method=smoothed, smoothing distance=300 meters. For additional details on these parameters, please see the DSAS help file distributed with the DSAS software.

   Date: 2020 (process 2 of 3)

   Rate calculations were performed using DSAS v5.0 in ArcMap v10.7 on selected shoreline features to derive a long-term (greater than 70 years) change rate based on data availability. Parameters Used: shoreline layer=BTI_Shoreline_19472020, shoreline date field=DATE_, shoreline uncertainty field name=UNCY, the default accuracy= 0 meters, stats calculations=all, confidence interval=90%. All statistics were calculated.

   Date: 2020 (process 3 of 3)

   Output transect feature classes with rate-of-change statistics were exported to a shapefile (BarterIsland_ShoreTransect_ChangeRates_1940to2020.shp). The attribute Calc_Yrs was added and populated.

3. What similar or related data should the user be aware of?
   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.

   Online Links:

   • https://doi.org/10.3133/ofr20151048

   Other_Citation_Details:

   Gibbs, A.E., and Richmond, B.M., 2015, National assessment of shoreline change—Historical shoreline change along the north coast of Alaska, U.S.–Canadian border to Icy Cape: U.S. Geological Survey Open-File Report 2015–1048, 96 p.

   Himmelstoss, Emily A., Henderson, Rachel E., Kratzmann, Meridith G., and Farris, Amy S., 2018, Digital Shoreline Analysis System (DSAS) version 5.0 user guide.

   Online Links:

   • https://doi.org/10.3133/ofr20181179

   Other_Citation_Details:

   Himmelstoss, E.A., Henderson, R.E., Kratzmann, M.G., and Farris, A.S., 2018, Digital Shoreline Analysis System (DSAS) version 5.0 user guide: U.S. Geological Survey Open-File Report 2018–1179.

   Gibbs, Ann E., Nolan, Matt, Richmond, Bruce M., Snyder, Alexander G., and Erikson, Li H., 2019, Assessing patterns of annual change to permafrost bluffs along the North Slope coast of Alaska using high-resolution imagery and elevation models.

   Online Links:

   • https://doi.org/10.1016/j.geomorph.2019.03.029

   Other_Citation_Details:

   Gibbs, A.E., Nolan, M., Richmond, B.M., Snyder, A.G., Erikson, L.H., 2019, Assessing patterns of annual change to permafrost bluffs along the North Slope coast of Alaska using high-resolution imagery and elevation models. Geomorphology, v. 336, p. 152-164.

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

1. How well have the observations been checked?
   The attributes in this layer is based on the requirements for use within the Digital Shoreline Analysis System (DSAS) software (Himmelstoss and others, 2018). The data have been quality checked.
2. How accurate are the geographic locations?
   The transect serves as a reference point along which measurements are calculated by the Digital Shoreline Analysis System (DSAS) software. It does not correspond to any real-world feature.
3. How accurate are the heights or depths?
   The transect serves as a reference point along which measurements are calculated by the Digital Shoreline Analysis System (DSAS) software. It does not correspond to any real-world feature.
4. Where are the gaps in the data? What is missing?
   This dataset contains transects automatically generated by the DSAS software application that can be used to calculate shoreline rate-of-change statistics where shoreline position data are available. Rate of change statistics were calculated only where transects intersected 6 shoreline dates selected to provide long-term rate of change rate over the entire date range and study area. Where transects did not intersect all 6 shoreline dates selected for this long-term change-rate analysis, rate of change statistics were not calculated and statistical attributes have a value of -9999. This transect dataset however can be used to calculate statistics for any different combination of years as required by the user.
5. How consistent are the relationships among the observations, including topology?
   All polylines have a unique identification attribute (FID). This field is used by the Digital Shoreline Analysis System (DSAS) to measure shoreline change.

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 - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? These data are available in shapefile format contained in a single zip file, which also includes CSDGM FGDC-compliant metadata.
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?
   • Availability in digital form:

     Data format:	Zip file contains shoreline change rates measured along shore perpendicular transects at Barter Island, Alaska. in format Vector Digital Data Set (Polyline) (version ArcGIS Desktop 10.7) Esri polyline shapefile Size: 2
     Network links:	https://www.sciencebase.gov/catalog/file/get/5fb716ded34eb413d5e143dd https://doi.org/10.5066/P9CRBC5I

   • 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: 04-Dec-2020

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-427-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)