2017 lidar-derived mean high water shoreline for the coast of North Carolina from the Virginia border to Cape Hatteras (NCnorth)

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?
Who produced the data set?
Why was the data set created?
How was the data set created?
How reliable are the data; what problems remain in the data set?
How can someone get a copy of the data set?
Who wrote the metadata?

What does this data set describe?

Title:

2017 lidar-derived mean high water shoreline for the coast of North Carolina from the Virginia border to Cape Hatteras (NCnorth)

Abstract:

The U.S. Geological Survey (USGS) has compiled national shoreline data for more than 20 years to document coastal change and serve the needs of research, management, and the public. Maintaining a record of historical shoreline positions is an effective method to monitor national shoreline evolution over time, enabling scientists to identify areas most susceptible to erosion or accretion. These data can help coastal managers and planners understand which areas of the coast are vulnerable to change.
This data release includes one new mean high water (MHW) shoreline extracted from lidar data collected in 2017 for the entire coastal region of North Carolina which is divided into four subregions: northern North Carolina (NCnorth), central North Carolina (NCcentral), southern North Carolina (NCsouth), and western North Carolina (NCwest). Previously published historical shorelines for North Carolina (Kratzmann and others, 2017) were combined with the new lidar shoreline to calculate long-term (up to 169 years) and short-term (up to 20 years) rates of change. Files associated with the long-term and short-term rates are appended with "LT" and "ST", respectively. A proxy-datum bias reference line that accounts for the positional difference in a proxy shoreline (e.g. High Water Line (HWL) shoreline) and a datum shoreline (e.g. MHW shoreline) is also included in this release.

Supplemental_Information:

Cross-referenced citations are applicable to the dataset as a whole.

How might this data set be cited?
Weber, Kathryn M., Farris, Amy S., and Bartlett, Marie K., 20231023, 2017 lidar-derived mean high water shoreline for the coast of North Carolina from the Virginia border to Cape Hatteras (NCnorth): data release doi:10.5066/P9HYNUNV, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.
Online Links:
- https://doi.org/10.5066/P9HYNUNV
- https://www.sciencebase.gov/catalog/item/64dfa9fdd34e5f6cd553bc64
This is part of the following larger work.
Bartlett, Marie K., Farris, Amy S., Weber, Kathryn M., and Henderson, Rachel E., 2023, USGS National Shoreline Change — 2017 lidar-derived mean high water shoreline and associated shoreline change data for coastal North Carolina: data release doi:10.5066/P9HYNUNV, U.S. Geological Survey, Reston, VA.
Online Links:
- https://doi.org/10.5066/P9HYNUNV
- https://www.sciencebase.gov/catalog/item/64de3810d34e5f6cd5533c78
Other_Citation_Details:
Bartlett, M.K., Farris, A.S., Weber, K.M., and Henderson, R.E., 2023, USGS National Shoreline Change — 2017 lidar-derived mean high water shoreline and associated shoreline change data for coastal North Carolina: U.S. Geological Survey data release, https://doi.org/P9HYNUNV.
What geographic area does the data set cover?
West_Bounding_Coordinate: -75.867349
East_Bounding_Coordinate: -75.458742
North_Bounding_Coordinate: 36.551142
South_Bounding_Coordinate: 35.216618
What does it look like?

https://www.sciencebase.gov/catalog/file/get/64dfa9fdd34e5f6cd553bc64?name=NCnorth_shoreline_2017_browse.PNG (PNG)
Map view of dataset.
Does the data set describe conditions during a particular time period?

Calendar_Date: 2017
Currentness_Reference:

ground condition at the time of survey
What is the general form of this data set?
Geospatial_Data_Presentation_Form: vector digital data
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 (11)
2. What coordinate system is used to represent geographic features?
  
  Grid_Coordinate_System_Name: Universal Transverse Mercator
  Universal_Transverse_Mercator:
  UTM_Zone_Number: 18
  Transverse_Mercator:
  Scale_Factor_at_Central_Meridian: 0.9996
  Longitude_of_Central_Meridian: -81.0
  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 meters
  The horizontal datum used is WGS_1984.
  The ellipsoid used is WGS_84.
  The semi-major axis of the ellipsoid used is 6378137.0.
  The flattening of the ellipsoid used is 1/298.257223563.
How does the data set describe geographic features?

NCnorth_shoreline_2017
This dataset includes polyline shoreline for 2017 extracted from lidar data for the North Carolina coastal region, extending from the northern border with Virginia to Cape Hatteras. (Source: U.S. Geological Survey (USGS))

FID
Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry. (Source: Esri) Feature geometry. This shoreline is a polyline shapefile.
Date_
Date of lidar survey from which the shoreline was extracted. (Source: USGS) Date is in mm/dd/yyyy format
Uncy
Estimate of shoreline position uncertainty in meters. Actual shoreline position is assumed to be within the range of this value (plus or minus, meters). Methods used to calculate the uncertainty are listed in the process steps. (Source: USGS)

Range of values

Minimum: 2.073

Maximum: 4.912

Units: meters

Source
Agency that provided shoreline feature or the data source used (e.g. lidar) to digitize shoreline feature. (Source: USGS)

Value Definition

USGS USGS provided the shoreline feature or the data source used to digitize shoreline feature.

Source_b
Method of deriving shoreline feature, if known. (Source: USGS)

Value Definition

Lidar Shoreline extraction from lidar

Year_
Four-digit year of shoreline. (Source: USGS)

Value Definition

2017 Year of lidar survey

Type
The vertical shoreline reference used for shoreline extraction. (Source: USGS)

Value Definition

MHW Mean high water - a datum-based elevation reference

Shape_Leng
Length of feature in meter units (WGS 1984 UTM Zone 18N) (Source: Esri)

Range of values

Minimum: 174.877

Maximum: 57804.579

Units: meters

Entity_and_Attribute_Overview:
The entity and attribute information provided here describes the tabular data associated with the dataset. Please review the individual attribute descriptions for detailed information.
Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Range of values
Minimum:	2.073
Maximum:	4.912
Units:	meters

Value	Definition
USGS	USGS provided the shoreline feature or the data source used to digitize shoreline feature.

Value	Definition
Lidar	Shoreline extraction from lidar

Value	Definition
2017	Year of lidar survey

Value	Definition
MHW	Mean high water - a datum-based elevation reference

Range of values
Minimum:	174.877
Maximum:	57804.579
Units:	meters

Who produced the data set?

Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
- Kathryn M. Weber
- Amy S. Farris
- Marie K. Bartlett
Who also contributed to the data set?
To whom should users address questions about the data?

Marie K. Bartlett

U.S. Geological Survey

Geologist

384 Woods Hole Rd
Woods Hole, MA

508-457-8700 x2306 (voice)

mbartlett@usgs.gov

Why was the data set created?

Historical shoreline positions are used to describe the movement of beaches through time and to maintain a national database of shoreline change. This shoreline dataset is a mean high water (MHW) datum-based shoreline extracted using a profile method (Farris and others, 2018) for 2017. The profile method extracts the MHW position from point cloud data using a Matlab based approach. This shoreline is used in conjunction with other shoreline files to calculate rates of shoreline change for coastal North Carolina.

How was the data set created?

From what previous works were the data drawn?
2017 NC Lidar (source 1 of 1)
NOAA Office for Coastal Management (NOAA/OCM), 20170913, 2017 USACE NCMP Topobathy Lidar: East Coast (NY, NJ, DE, MD, VA, NC, SC, GA): NOAA's Ocean Service, Coastal Services Center (CSC), Charleston, SC.
Online Links:
- https://www.fisheries.noaa.gov/inport/item/52444
Type_of_Source_Media: Digital
Source_Contribution:
The bare-earth lidar point cloud data in LAS format were used to extract shorelines using methods described in the process steps. The data were downloaded using the cart feature in UTM Zone 18 projection with NAD83 horizontal datum and NAVD88 vertical datum (meters).
How were the data generated, processed, and modified?
Date: 2022 (process 1 of 3)
Step 1: MHW shorelines are datum-based and in the case of the 2017 shoreline, are extracted from lidar data using a profile method, described in Farris and others (2018). The appropriate MHW elevation values were obtained from Weber and others (2005). From the northern border with Virginia to Cape Lookout the MHW elevation is 0.26 m. From Cape Lookout to Cape Fear, the MHW elevation is 0.36 m. From Cape Fear to the southern border with South Carolina the MHW elevation is 0.51 m. Person who carried out this activity:

Marie K. Bartlett

U.S. Geological Survey

384 Woods Hole Rd
Woods Hole, MA

508-548-8700 x 2306 (voice)

mbartlett@usgs.gov

Date: 2022 (process 2 of 3)
Step 2: The profile method used a coast-following reference line with 20-meter spaced profiles. All lidar data points that were within 1 meter of each profile line were associated with that profile. All processing was done on the 2-meter-wide profiles, working on a single profile at a time. For each profile, a linear regression was fit through data points on the foreshore and the regression was evaluated at the MHW elevation to yield the cross-shore position of the MHW shoreline. If there was a data gap at MHW or if the MHW elevation was obscured by water points, the linear regression was simply extrapolated to the MHW elevation. For each profile, the foreshore beach slope was defined as the slope of the regression line. This slope is stored and later used for the calculation of the proxy-datum bias feature. Each MHW shoreline point that was extracted using this profile method has an uncertainty associated with it. See the horizontal accuracy section of the metadata for details on how the uncertainty is calculated. The 2017 shoreline was extracted by Kathryn M. Weber Person who carried out this activity:

Kathryn Weber

U.S. Geological Survey

384 Woods Hole Rd
Woods Hole, MA

508-548-8700 (voice)

kweber@usgs.gov

Data sources used in this process:
- 2017 NC Lidar
Date: 2022 (process 3 of 3)
Step 3: The 2017 shoreline was imported into a personal geodatabase in ArcMap v10.7.1 for use in shoreline change analysis. Then, the 2017 shoreline was exported to a shapefile for publication in ArcMap v10.7.1. Coordinate system: WGS 84 UTM Zone 18N (NCnorth, NCcentral, NCsouth) or WGS 84 UTM Zone 17N (NCwest). Person who carried out this activity:

Marie K. Bartlett

U.S. Geological Survey

384 Woods Hole Rd
Woods Hole, MA

508-548-8700 x 2306 (voice)

mbartlett@usgs.gov
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, Zichichi, Jessica L., and Thieler, E. Robert, 2018, Digital Shoreline Analysis System (version 5.1): U.S. Geological Survey Software: software release version 5.1, U.S. Geological Survey, Reston, VA.
Online Links:
Other_Citation_Details:
Use the first two links to access the software. The third link directs to the DSAS project page. Current software at time of use was 5.1.
Himmelstoss, Emily A., Henderson, Rachel E., Kratzmann, Meredith G., and Farris, Amy S., 20211019, Digital Shoreline Analysis System (DSAS) version 5.1 User Guide: Open-File Report 2021-1091, U.S. Geological Survey, Reston, VA.
Online Links:
Other_Citation_Details:
Use the first two access the user guide. The third link directs to the DSAS project page.
Farris, Amy S., Weber, Kathryn M., Doran, Kara S., and List, Jeffrey H., 2018, Comparing Methods Used by the U.S. Geological Survey Coastal and Marine Geology Program for Deriving Shoreline Position from Lidar Data: Open-File Report 2018-1121, U.S. Geological Survey, Reston, VA.
Online Links:
- https://doi.org/10.3133/ofr20181121
Kratzmann, Meredith G., Himmelstoss, Emily A., and Thieler, E. Robert, 2017, National assessment of shoreline change – A GIS compilation of updated vector shorelines and associated shoreline change data for the Southeast Atlantic Coast: data release 2017, U.S. Geological Survey, Reston, VA.
Online Links:
- https://doi.org/10.5066/F74X55X7
- https://www.sciencebase.gov/catalog/item/58055f50e4b0824b2d1c1ee7
Weber, Kathryn M., List, Jeffrey H., and Morgan, Karen L.M., 2005, An operational mean high water datum for determination of shoreline position from topographic Lidar data: Open-File Report 2005-1027, U.S. Geological Survey, Reston, VA.
Online Links:
- https://doi.org/10.3133/ofr20051027
- https://pubs.usgs.gov/of/2005/1027/

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

How well have the observations been checked?
The attributes are based on the requirements of the Digital Shoreline Analysis System (DSAS) which include a date and uncertainty value.
How accurate are the geographic locations?
Positional uncertainty associated with the 2017 lidar shoreline was calculated at each transect and includes four components: 1) the 95% confidence interval on the linear regression estimate of the shoreline position; 2) the vertical error of the raw lidar data as reported in the metadata; 3) a 15 cm vertical error in our chosen value of MHW, and; 4) the uncertainty due to extrapolation (if the shoreline was determined using extrapolation).These four components of uncertainty were added in quadrature to yield a total error for each shoreline point.
How accurate are the heights or depths?
Where are the gaps in the data? What is missing?
This shoreline dataset is a mean high water (MHW) datum-based shoreline extracted using the profile method (Farris and others 2018). See process steps for description of use. Although not a continuous shoreline for the entire coast of North Carolina, this shoreline file is complete and contains all shoreline segments used to calculate shoreline change rates along sections of the North Carolina coastal region where lidar data were available. These data adequately represented the shoreline position at the time of the survey. Gaps in these shoreline data represent a lack of data or data that did not meet quality assurance standards.
How consistent are the relationships among the observations, including topology?
Adjacent shoreline segments do not overlap and are not necessarily continuous. Shorelines were visually assessed in map view to verify that no erroneous data were included. These data contain some short line segments (less than 30 meters) that were part of how the data were originally compiled and are the correct shoreline positions.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints	None.
Use_Constraints	Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset. These data are not to be used for navigation.

Who distributes the data set? (Distributor 1 of 1)

U.S. Geological Survey

Attn: USGS ScienceBase

Denver Federal Center, Building 810, Mail Stop 302
Denver, CO

United States

1-888-275-8747 (voice)

sciencebase@usgs.gov
What's the catalog number I need to order this data set? The dataset contains the polyline shapefile of the 2017 North Carolina lidar shoreline used to calculate long and short-term rates of change (NCnorth_shoreline_2017.shp and other shapefile components), browse graphic (NCnorth_shoreline_2017_browse.PNG), and the FGDC CSDGM metadata in XML format.
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.

How can I download or order the data?

Availability in digital form:

Data format:	These files (.cpg, .dbf, .prj, .sbn, .sbx, .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. Additional files of the same name included are FGDC CSDGM-compliant metadata in XML format. in format Shapefile (version ArcGIS 10.7.1) Esri polyline shapefile Size: 0.1
Network links:	https://doi.org/10.5066/P9HYNUNV https://www.sciencebase.gov/catalog/file/get/64dfa9fdd34e5f6cd553bc64 https://www.sciencebase.gov/catalog/item/64dfa9fdd34e5f6cd553bc64

Cost to order the data: none

Who wrote the metadata?

Dates:

Last modified: 23-Oct-2023

Metadata author:

Marie K. Bartlett

U.S. Geological Survey

384 Woods Hole Rd

Woods Hole, MA

USA

508-548-8700 x2306 (voice)

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.

Metadata standard:

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

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P9HYNUNV/NCnorth_shoreline_2017.faq.html>