Long-term and short-term shoreline change rates for the region of Martha's Vineyard, Massachusetts, calculated with and without the proxy-datum bias using the Digital Shoreline Analysis System version 5.1

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What does this data set describe?

1. How might this data set be cited?
   U.S. Geological Survey, 20210831, Long-term and short-term shoreline change rates for the region of Martha's Vineyard, Massachusetts, calculated with and without the proxy-datum bias 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:

   • https://doi.org/10.5066/P9YGIYFX
   • https://www.sciencebase.gov/catalog/item/610829f2d34ef8d70565ba19

   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:

   • https://www.sciencebase.gov/catalog/item/60ff22dad34e3ccd830d62aa
   • https://doi.org/10.5066/P9YGIYFX

   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: -70.8390
   East_Bounding_Coordinate: -70.4463
   North_Bounding_Coordinate: 41.4827
   South_Bounding_Coordinate: 41.2490
   

3. What does it look like?

   https://www.sciencebase.gov/catalog/file/get/610829f2d34ef8d70565ba19?name=MarthasVineyard_rates_browse.PNG (PNG)

   Map view of data

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

   Calendar_Date: 2021

   Currentness_Reference:

   ground condition of the most recent shoreline these rates are based on

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 0.0197422351. Longitudes are given to the nearest 0.0261997981. 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?

   MarthasVN_rates_LT.shp

   Rates of long-term shoreline change are calculated by DSAS and stored in the transect file, using the distance measurements between shorelines and baseline at each DSAS transect. These attributes are for long-term rates with and without bias applied. The shapefiles will have LT for long-term in filename. Vector Object Count: 1404 (Source: U.S. Geological Survey)

   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

   Feature geometry (Source: Esri) Coordinates defining the features.

   TransectID

   A unique identification number for each transect. Values may not increment sequentially alongshore. (Source: U.S. Geological Survey) Sequential unique whole numbers that are automatically generated.

   BaselineID

   Unique identification number of the baseline segment. If BaselineID=0 no transects will be generated. Used by DSAS to determine transect ordering alongshore if multiple baseline segments exist. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	1
   Maximum:	unlimited

   GroupID

   This optional field is a way to aggregate transects on the basis of physical variations alongshore (for example, tidal inlets, change in coastal type, or hard stabilization features). This value was assigned by the user as an attribute to a baseline segment and results in a group average being reported in the DSAS summary text file. (Source: U.S. Geological Survey)

   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: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   Azimuth

   Assigned by DSAS to record the azimuth of the transect measure in degrees clockwise from North. If a transect position has been adjusted during the editing process, the azimuth value in the attribute table is updated automatically. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	360
   Units:	Degrees

   ShrCount

   Number of shorelines used to compute shoreline change metrics. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	3
   Maximum:	unlimited

   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: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   SHAPE_Length

   Length of feature in meter units (UTM zone 19N, WGS 84) (Source: Esri)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   LRR

   A linear regression rate-of-change statistic was calculated by fitting a least-squares regression line to all shoreline points for a particular transect. Any shoreline points that are referenced to HWL were adjusted by the proxy-datum bias distance (meters) along the transect to correct for the offset between proxy-based HWL and datum-based MHW shorelines. The best-fit regression line is placed so that the sum of the squared residuals (determined by squaring the offset distance of each data point from the regression line and adding the squared residuals together) is minimized. The linear regression rate is the slope of the line. The rate is reported in meters per year with positive values indicating accretion and negative values indicating erosion. LRR calculations require a minimum of 3 shorelines; less than 3 shorelines results in a “null” value, which is not a supported value in shapefile format . A value of 9999 in the LRR attribute field along with a ShRCount of 2 indicates the required number of shorelines to compute the linear regression rate was not met. (Source: U.S. Geological Survey) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   NB_LRR

   The LRR without the bias applied. (Source: U.S. Geological Survey) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   LR2

   The R-squared statistic, or coefficient of determination, is the percentage of variance in the data that is explained by a regression. It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	1

   NB_LR2

   The LR2 without the bias applied. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	1

   LSE

   The predicted (or estimated) values of y (the distance from baseline in meters) are computed for each shoreline point by using the values of x (the shoreline date) and solving the equation for the best-fit regression line (y=mx+b). The standard error is also called the standard deviation. (Source: U.S. Geological Survey) Positive decimal values in meters.

   NB_LSE

   The LSE without the bias applied. (Source: U.S. Geological Survey) Positive decimal values in meters.

   LCI90

   The standard error of the slope with confidence interval describes the uncertainty of the reported rate. The LRR rates are determined by a best-fit regression line for the shoreline data at each transect. The slope of this line is the reported rate of change (in meters/year). The confidence interval (LCI) is calculated by multiplying the standard error (also called the standard deviation) of the slope by the two-tailed test statistic at the user-specified 90 percent confidence. This value is often reported in conjunction with the slope to describe the confidence of the reported rate. For example: LRR = 1.2 LCI90 = 0.7 could be reported as a rate of 1.2 (+/-) 0.7 meters/year. (Source: U.S. Geological Survey) Positive decimal values in meters

   NB_LCI90

   The LCI at the user-selected confidence value without the bias applied. (Source: U.S. Geological Survey) Positive decimal values in meters

   MarthasVN_rates_ST.shp

   Rates of short-term shoreline change are calculated by DSAS and stored in the transect file, using the distance measurements between shorelines and baseline at each DSAS transect. These attributes are for short-term rates with and without bias applied. The shapefiles will have ST for short-term in filename. Vector object count: 1400 (Source: U.S. Geological Survey)

   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

   Feature geometry. (Source: ESRI) Coordinates defining the features.

   TransectID

   A unique identification number for each transect. Values may not increment sequentially alongshore. (Source: USGS) Sequential unique whole numbers that are automatically generated.

   BaselineID

   Unique identification number of the baseline segment. If BaselineID=0 no transects will be generated. Used by DSAS to determine transect ordering alongshore if multiple baseline segments exist. (Source: USGS)

   Range of values
   Minimum:	1
   Maximum:	unlimited

   GroupID

   This optional field is a way to aggregate transects on the basis of physical variations alongshore (for example, tidal inlets, change in coastal type, or hard stabilization features). This value was assigned by the user as an attribute to a baseline segment and results in a group average being reported in the DSAS summary text file. (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

   Azimuth

   Assigned by DSAS to record the azimuth of the transect measure in degrees clockwise from North. If a transect position has been adjusted during the editing process, the azimuth value in the attribute table is updated automatically. (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	360

   ShrCount

   Number of shorelines used to compute shoreline change metrics. (Source: USGS)

   Range of values
   Minimum:	2
   Maximum:	unlimited

   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: USGS)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   EPR

   The end point rate (EPR) is calculated by determining the distance between the oldest and youngest shoreline on a DSAS transect and dividing by the time elapsed between the two shoreline dates. (Source: U.S. Geological Survey) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   NB_EPR

   EPR without the bias applied. (Source: U.S. Geological Survey) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   EPRunc

   An estimate of end point rate uncertainty. The shoreline uncertainties for the two positions used in the end point calculation are each squared, then added together (summation of squares). The square root of the summation of squares is divided by the number of years between the two shorelines. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   NB_EPRunc

   EPRunc without the bias applied. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   LRR

   A linear regression rate-of-change statistic was calculated by fitting a least-squares regression line to all shoreline points for a particular transect. Any shoreline points that are referenced to HWL were adjusted by the proxy-datum bias distance (meters) along the transect to correct for the offset between proxy-based HWL and datum-based MHW shorelines. The best-fit regression line is placed so that the sum of the squared residuals (determined by squaring the offset distance of each data point from the regression line and adding the squared residuals together) is minimized. The linear regression rate is the slope of the line. The rate is reported in meters per year with positive values indicating accretion and negative values indicating erosion. LRR calculations require a minimum of 3 shorelines; less than 3 shorelines results in a “null” value, which is not a supported value in shapefile format . A value of 9999 in the LRR attribute field along with a ShRCount of 2 indicates the required number of shorelines to compute the linear regression rate was not met. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   NB_LRR

   LRR without the bias applied. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   LR2

   The R-squared statistic, or coefficient of determination, is the percentage of variance in the data that is explained by a regression. It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	1

   NB_LR2

   LR2 without the bias applied (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	1

   LSE

   The predicted (or estimated) values of y (the distance from baseline in meters) are computed for each shoreline point by using the values of x (the shoreline date) and solving the equation for the best-fit regression line (y=mx+b). The standard error is also called the standard deviation. (Source: USGS) Positive decimal values in meters.

   NB_LSE

   LSE without the bias applied. (Source: USGS) Positive decimal values in meters.

   LCI90

   The standard error of the slope with confidence interval describes the uncertainty of the reported rate. The LRR rates are determined by a best-fit regression line for the shoreline data at each transect. The slope of this line is the reported rate of change (in meters/year). The confidence interval (LCI) is calculated by multiplying the standard error (also called the standard deviation) of the slope by the two-tailed test statistic at the user-specified 90 percent confidence. This value is often reported in conjunction with the slope to describe the confidence of the reported rate. For example: LRR = 1.2 LCI90 = 0.7 could be reported as a rate of 1.2 (+/-) 0.7 meters/year. (Source: USGS) Positive decimal values in meters.

   NB_LCI90

   LC190 without the bias applied. (Source: USGS) Positive decimal values in meters.

   SHAPE_Leng

   Length of feature in meter units (UTM zone 19N, WGS 84) (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   MarthasVS_rates_LT.shp

   Rates of long-term shoreline change are calculated by DSAS and stored in the transect file, using the distance measurements between shorelines and baseline at each DSAS transect. These attributes are for long-term rates with and without bias applied. The shapefiles will have LT for short-term in filename. Vector object count: 1041 (Source: U.S. Geological Survey)

   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

   Feature geometry. (Source: ESRI) Coordinates defining the features.

   TransectID

   A unique identification number for each transect. Values may not increment sequentially alongshore. (Source: USGS) Sequential unique whole numbers that are automatically generated.

   BaselineID

   Unique identification number of the baseline segment. If BaselineID=0 no transects will be generated. Used by DSAS to determine transect ordering alongshore if multiple baseline segments exist. (Source: USGS)

   Range of values
   Minimum:	1
   Maximum:	unlimited

   GroupID

   This optional field is a way to aggregate transects on the basis of physical variations alongshore (for example, tidal inlets, change in coastal type, or hard stabilization features). This value was assigned by the user as an attribute to a baseline segment and results in a group average being reported in the DSAS summary text file. (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

   Azimuth

   Assigned by DSAS to record the azimuth of the transect measure in degrees clockwise from North. If a transect position has been adjusted during the editing process, the azimuth value in the attribute table is updated automatically. (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	360

   ShrCount

   Number of shorelines used to compute shoreline change metrics. (Source: USGS)

   Range of values
   Minimum:	2
   Maximum:	unlimited

   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: USGS)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   LRR

   A linear regression rate-of-change statistic was calculated by fitting a least-squares regression line to all shoreline points for a particular transect. Any shoreline points that are referenced to HWL were adjusted by the proxy-datum bias distance (meters) along the transect to correct for the offset between proxy-based HWL and datum-based MHW shorelines. The best-fit regression line is placed so that the sum of the squared residuals (determined by squaring the offset distance of each data point from the regression line and adding the squared residuals together) is minimized. The linear regression rate is the slope of the line. The rate is reported in meters per year with positive values indicating accretion and negative values indicating erosion. LRR calculations require a minimum of 3 shorelines; less than 3 shorelines results in a “null” value, which is not a supported value in shapefile format . A value of 9999 in the LRR attribute field along with a ShRCount of 2 indicates the required number of shorelines to compute the linear regression rate was not met. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   NB_LRR

   LRR without the bias applied. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   LR2

   The R-squared statistic, or coefficient of determination, is the percentage of variance in the data that is explained by a regression. It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	1

   NB_LR2

   LR2 without the bias applied (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	1

   LSE

   The predicted (or estimated) values of y (the distance from baseline in meters) are computed for each shoreline point by using the values of x (the shoreline date) and solving the equation for the best-fit regression line (y=mx+b). The standard error is also called the standard deviation. (Source: USGS) Positive decimal values in meters.

   NB_LSE

   LSE without the bias applied. (Source: USGS) Positive decimal values in meters.

   LCI90

   The standard error of the slope with confidence interval describes the uncertainty of the reported rate. The LRR rates are determined by a best-fit regression line for the shoreline data at each transect. The slope of this line is the reported rate of change (in meters/year). The confidence interval (LCI) is calculated by multiplying the standard error (also called the standard deviation) of the slope by the two-tailed test statistic at the user-specified 90 percent confidence. This value is often reported in conjunction with the slope to describe the confidence of the reported rate. For example: LRR = 1.2 LCI90 = 0.7 could be reported as a rate of 1.2 (+/-) 0.7 meters/year. (Source: USGS) Positive decimal values in meters.

   NB_LCI90

   LC190 without the bias applied. (Source: USGS) Positive decimal values in meters.

   SHAPE_Leng

   Length of feature in meter units (UTM zone 19N, WGS 84) (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   MarthasVS_rates_ST.shp

   Rates of short-term shoreline change are calculated by DSAS and stored in the transect file, using the distance measurements between shorelines and baseline at each DSAS transect. These attributes are for short-term rates with and without bias applied. The shapefiles will have ST for short-term in filename. Vector object count: 1041 (Source: U.S. Geological Survey)

   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

   Feature geometry. (Source: ESRI) Coordinates defining the features.

   TransectID

   A unique identification number for each transect. Values may not increment sequentially alongshore. (Source: USGS) Sequential unique whole numbers that are automatically generated.

   BaselineID

   Unique identification number of the baseline segment. If BaselineID=0 no transects will be generated. Used by DSAS to determine transect ordering alongshore if multiple baseline segments exist. (Source: USGS)

   Range of values
   Minimum:	1
   Maximum:	unlimited

   GroupID

   This optional field is a way to aggregate transects on the basis of physical variations alongshore (for example, tidal inlets, change in coastal type, or hard stabilization features). This value was assigned by the user as an attribute to a baseline segment and results in a group average being reported in the DSAS summary text file. (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

   Azimuth

   Assigned by DSAS to record the azimuth of the transect measure in degrees clockwise from North. If a transect position has been adjusted during the editing process, the azimuth value in the attribute table is updated automatically. (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	360

   ShrCount

   Number of shorelines used to compute shoreline change metrics. (Source: USGS)

   Range of values
   Minimum:	2
   Maximum:	unlimited

   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: USGS)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   EPR

   The end point rate (EPR) is calculated by determining the distance between the oldest and youngest shoreline on a DSAS transect and dividing by the time elapsed between the two shoreline dates. (Source: U.S. Geological Survey) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   NB_EPR

   EPR without the bias applied. (Source: U.S. Geological Survey) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   EPRunc

   An estimate of end point rate uncertainty. The shoreline uncertainties for the two positions used in the end point calculation are each squared, then added together (summation of squares). The square root of the summation of squares is divided by the number of years between the two shorelines. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   NB_EPRunc

   EPRunc without the bias applied. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	unlimited

   LRR

   A linear regression rate-of-change statistic was calculated by fitting a least-squares regression line to all shoreline points for a particular transect. Any shoreline points that are referenced to HWL were adjusted by the proxy-datum bias distance (meters) along the transect to correct for the offset between proxy-based HWL and datum-based MHW shorelines. The best-fit regression line is placed so that the sum of the squared residuals (determined by squaring the offset distance of each data point from the regression line and adding the squared residuals together) is minimized. The linear regression rate is the slope of the line. The rate is reported in meters per year with positive values indicating accretion and negative values indicating erosion. LRR calculations require a minimum of 3 shorelines; less than 3 shorelines results in a “null” value, which is not a supported value in shapefile format . A value of 9999 in the LRR attribute field along with a ShRCount of 2 indicates the required number of shorelines to compute the linear regression rate was not met. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   NB_LRR

   LRR without the bias applied. (Source: USGS) Decimal values may be positive or negative, which is used to indicate landward (negative) or seaward (positive) direction from baseline origin. Reported in meters per year.

   LR2

   The R-squared statistic, or coefficient of determination, is the percentage of variance in the data that is explained by a regression. It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	1

   NB_LR2

   LR2 without the bias applied (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	1

   LSE

   The predicted (or estimated) values of y (the distance from baseline in meters) are computed for each shoreline point by using the values of x (the shoreline date) and solving the equation for the best-fit regression line (y=mx+b). The standard error is also called the standard deviation. (Source: USGS) Positive decimal values in meters.

   NB_LSE

   LSE without the bias applied. (Source: USGS) Positive decimal values in meters.

   LCI90

   The standard error of the slope with confidence interval describes the uncertainty of the reported rate. The LRR rates are determined by a best-fit regression line for the shoreline data at each transect. The slope of this line is the reported rate of change (in meters/year). The confidence interval (LCI) is calculated by multiplying the standard error (also called the standard deviation) of the slope by the two-tailed test statistic at the user-specified 90 percent confidence. This value is often reported in conjunction with the slope to describe the confidence of the reported rate. For example: LRR = 1.2 LCI90 = 0.7 could be reported as a rate of 1.2 (+/-) 0.7 meters/year. (Source: USGS) Positive decimal values in meters.

   NB_LCI90

   LC190 without the bias applied. (Source: USGS) Positive decimal values in meters.

   SHAPE_Leng

   Length of feature in meter units (UTM zone 19N, WGS 84) (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 long-term (greater than 50 years, and typically closer to 100 years) and short-term (approximately 30 years) shoreline change rates. Rate statistics are presented with and without the proxy-datum bias, distinguished by fields containing “NB_” for “no bias” in the attribute table. 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 rates, long-term (150+ years) and short-term (~30 years).

   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?
   Marie K. Bartlett

   USGS

   Geologist

   384 Woods Hole Rd

   Woods Hole, MA
   

   USA

   508-548-8700 x2306 (voice)

   508-547-2310 (FAX)

   mbartlett@usgs.gov

Why was the data set created?

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:

   • https://doi.org/10.5066/P9O8QA8N
   • https://www.sciencebase.gov/catalog/item/60ff09abd34e3ccd830d5dac

   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

   MarthasVN_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 Martha's Vineyard, 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:

   • https://doi.org/10.5066/P9YGIYFX
   • https://www.sciencebase.gov/catalog/item/61082f8ed34ef8d70565bbf3

   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

   MarthasVS_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 Martha's Vineyard, 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:

   • https://doi.org/10.5066/P9YGIYFX
   • https://www.sciencebase.gov/catalog/item/610832dfd34ef8d70565bf42

   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 rate transect files that hold 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. Form 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 corresponding intersect file 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: 2021 (process 2 of 11)

   Transect features generated in a personal geodatabase using DSAS v5.1.2020.0720.0030. Parameters Used: baseline layer= MarthasVN_baseline, baseline group field=DSAS_group, transect spacing=50 meters, search distance=200 meters, land direction=left, shoreline intersection=seaward, File produced = MarthasVN_transects_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
   • MarthasVN_baseline

   Data sources produced in this process:

   • MarthasVN_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 = MarthasVN_trans_LT_rates_20210318_133812, MarthasVN_trans_LT_intersect_20210318_133812. 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
   • MarthasVN_transects_LT

   Data sources produced in this process:

   • MarthasVN_trans_rates_LT
   • MarthasVN_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= MarthasVN_baseline, baseline group field=DSAS_group, transect spacing=50 meters, search distance=200 meters, land direction=left, shoreline intersection=seaward, File produced = MarthasVN_transects_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
   • MarthasVN_baseline

   Data sources produced in this process:

   • MarthasVN_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 = MarthasVN_trans_ST_rates_20210322_151603, MarthasVN_trans_ST_intersect_20210322_151603. 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
   • MarthasVN_transects_ST

   Data sources produced in this process:

   • MarthasVN_trans_rates_ST
   • MarthasVN_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= MarthasVS_baseline, baseline group field=DSAS_group, transect spacing=50 meters, search distance=200 meters, land direction=left, shoreline intersection=seaward, File produced = MarthasVS_transects_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
   • MarthasVS_baseline

   Data sources produced in this process:

   • MarthasVS_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 = MarthasVS_trans_rates_LT_20210702_122450, MarthasVS_trans_LT_intersect_20210702_122450. 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
   • MarthasVS_transects_LT

   Data sources produced in this process:

   • MarthasVS_trans_rates_LT
   • MarthasVS_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= MarthasVS_baseline, baseline group field=DSAS_group, transect spacing=50 meters, search distance=200 meters, land direction=left, shoreline intersection=seaward, File produced = MarthasVS_transects_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
   • MarthasVS_baseline

   Data sources produced in this process:

   • MarthasVS_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 = MarthasVS_trans_rates_ST_20210702_124821, MarthasVS_intersect_ST_20210702_124821. 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
   • MarthasVS_transects_ST

   Data sources produced in this process:

   • MarthasVS_trans_rates_ST
   • MarthasVS_intersects_ST

   Date: 2021 (process 10 of 11)

   The rate 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 rate 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:

   • MarthasVN_trans_rates_LT
   • MarthasVN_trans_rates_ST
   • MarthasVS_trans_rates_LT
   • MarthasVS_trans_rates_ST

   Data sources produced in this process:

   • MarthasVN_rates_LT
   • MarthasVN_rates_ST
   • MarthasVS_rates_LT
   • MarthasVS_rates_ST

3. What similar or related data should the user be aware of?
   Himmelstoss, E.A., Farris, A.S., Henderson, R.E., Kratzmann, M.G., Ergul, A., Zhang, O., Zichichi, J.L., and Thieler, E.R., 2018, Digital Shoreline Analysis System (version 5): U.S. Geological Survey software: software version 5, U.S. Geological Survey, Coastal and Marine Geology Program, Reston, VA.

   Online Links:

   • https://code.usgs.gov/cch/dsas/
   • https://doi.org/10.5066/P9VW42I0

   Other_Citation_Details:

   Suggested citation: Himmelstoss, E.A., Farris, A.S., Henderson, R.E., Kratzmann, M.G., Ergul, A., Zhang, O., Zichichi, J.L., and Thieler, E.R., 2018, Digital Shoreline Analysis System (ver. 5.0): U.S. Geological Survey software, https://doi.org/10.5066/P9VW42I0 .

   Himmelstoss, E.A., Henderson, R.E., Kratzmann, M.G., and Farris, A., 2018, Digital Shoreline Analysis System (DSAS) Version 5 User Guide: Open File Report 2018-1179, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole, MA.

   Online Links:

   • https://doi.org/10.3133/ofr20181179
   • https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas

   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

   Thieler, E.R., Smith, T.I., Knisel, Julia, and Sampson, D.W., 2013, Massachusetts Shoreline Change Mapping and Analysis Project, 2012 Update: Open-File Report 2012-1189, U.S. Geological Survey, Reston, VA.

   Online Links:

   • http://pubs.usgs.gov/of/2012/1189/

   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, Reston, VA.

   Online Links:

   • https://doi.org/10.5066/P9O7S72B
   • https://www.sciencebase.gov/catalog/item/5bcde5dce4b0f0758fc178d0
   • https://www.sciencebase.gov/catalog/file/get/5bcde5dce4b0f0758fc178d0

   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:

   • https://doi.org/10.2112/08-1051.1

   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.

   Online Links:

   • https://doi.org/10.5066/P9RRBEYK.
   • https://www.sciencebase.gov/catalog/item/5c657589e4b0fe48cb38fc74

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 transect layer or during the calculation of shoreline change rates performed by the software.
2. How accurate are the geographic locations?
   The uncertainty of the linear regression rate is estimated by the elements LR2, LSE and LCI90_0. See the attribute definition of each for more information.
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   This dataset contains the transects automatically generated by the DSAS software application that were used to calculate shoreline change rates for the region. Additional transects may have been generated but did not intersect the minimum requirement of three shorelines. Shoreline change rates data are provided where there are available shorelines to compute change metrics.
5. How consistent are the relationships among the observations, including topology?
   These data were generated using DSAS v5.1. The transects automatically generated by the software were visually inspected along with the shoreline data prior to rate calculations. Sometimes transect positions were manually edited within a standard ArcMap edit session to adjust the position at which an individual transect intersected the shorelines to better represent an orthogonal position to the general trend of the coast over time.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Federal Center, Building 810, MS 302

   Denver, CO
   

   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 rate transect features used to store shoreline change 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?
   • Availability in digital form:

     Data format:	These files (.cpg, .dbf, .prj, .sbn, .sbx, .shp, .shp., and .shx) are a collection of files with a common filename prefix and must be downloaded and stored in the same directory. Together they are the components of the shapefile and include FGDC CSDGM-compliant metadata. in format Shapefile (version ArcGIS 10.7.1) Esri point shapefile Size: 1
     Network links:	https://www.sciencebase.gov/catalog/file/get/610829f2d34ef8d70565ba19 https://www.sciencebase.gov/catalog/item/610829f2d34ef8d70565ba19 https://doi.org/10.5066/P9YGIYFX

   • Cost to order the data: none

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:

U.S. Geological Survey

Attn: Marie Bartlett

Geologist

384 Woods Hole Rd

Woods Hole, MA

USA

508-548-8700 x2306 (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 person is no longer with USGS. (updated on 20240319)

Metadata standard:

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