Kathryn M. Weber Amy S. Farris Marie K. Bartlett 20231023 1.0 vector digital data data release doi:10.5066/P9HYNUNV Woods Hole Coastal and Marine Science Center, Woods Hole, MA U.S. Geological Survey, Coastal and Marine Hazards and Resources Program https://doi.org/10.5066/P9HYNUNV https://www.sciencebase.gov/catalog/item/64de6fe0d34e5f6cd55350c8 Marie K. Bartlett Amy S. Farris Kathryn M. Weber Rachel E. Henderson 2023 1.0 vector digital data data release doi:10.5066/P9HYNUNV Reston, VA U.S. Geological Survey 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. https://doi.org/10.5066/P9HYNUNV https://www.sciencebase.gov/catalog/item/64de3810d34e5f6cd5533c78 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. 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. Cross-referenced citations are applicable to the dataset as a whole. 2017 ground condition at the time of survey Complete None planned -78.542788 -78.013989 33.923098 33.839066 ISO 19115 Topic Category environment oceans geoscientificInformation None Shoreline Shoreline Change Digital Shoreline Analysis System DSAS U.S. Geological Survey USGS Woods Hole Coastal and Marine Science Center WHCMSC Mean High Water MHW USGS Thesaurus geospatial datasets coastal processes USGS Metadata Identifier USGS:64de6fe0d34e5f6cd55350c8 None Atlantic Coast United States North Carolina None. 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. Marie K. Bartlett U.S. Geological Survey Geologist mailing

384 Woods Hole Rd

Woods Hole MA 02543 508-457-8700 x2306 mbartlett@usgs.gov https://www.sciencebase.gov/catalog/file/get/64de6fe0d34e5f6cd55350c8?name=NCwest_shoreline_2017_browse.PNG Map view of dataset. PNG Microsoft Windows 10 Esri ArcGIS 10.7.1 Emily A. Himmelstoss Amy S. Farris Rachel E. Henderson Meredith G. Kratzmann Ayhan Ergul Ouya Zhang Jessica L. Zichichi E. Robert Thieler 2018 publication software release version 5.1 Reston, VA U.S. Geological Survey 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. https://doi.org/10.5066/P9VW42I0 https://code.usgs.gov/cch/dsas/ https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas Emily A. Himmelstoss Rachel E. Henderson Meredith G. Kratzmann Amy S. Farris 20211019 publication Open-File Report 2021-1091 Reston, VA U.S. Geological Survey Use the first two access the user guide. The third link directs to the DSAS project page. https://doi.org/10.3133/ofr20211091 https://pubs.er.usgs.gov/publication/ofr20211091 https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas Amy S. Farris Kathryn M. Weber Kara S. Doran Jeffrey H. List 2018 1 publication Open-File Report 2018-1121 Reston, VA U.S. Geological Survey https://doi.org/10.3133/ofr20181121 https://pubs.usgs.gov/of/2018/1121/ Meredith G. Kratzmann Emily A. Himmelstoss E. Robert Thieler 2017 vector digital data data release 2017 Reston, VA U.S. Geological Survey https://doi.org/10.5066/F74X55X7 https://www.sciencebase.gov/catalog/item/58055f50e4b0824b2d1c1ee7 Kathryn M. Weber Jeffrey H. List Karen L.M. Morgan 2005 1.0 publication Open-File Report 2005-1027 Reston, VA U.S. Geological Survey https://doi.org/10.3133/ofr20051027 https://pubs.usgs.gov/of/2005/1027/ The attributes are based on the requirements of the Digital Shoreline Analysis System (DSAS) which include a date and uncertainty value. 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. 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. 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. NOAA Office for Coastal Management (NOAA/OCM) 20170913 raster digital data Charleston, SC NOAA's Ocean Service, Coastal Services Center (CSC) https://www.fisheries.noaa.gov/inport/item/52444 Digital 20170609 20170916 ground condition at the time of survey 2017 NC Lidar 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 17 projection with NAD83 horizontal datum and NAVD88 vertical datum (meters). 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. 2022 Marie K. Bartlett U.S. Geological Survey mailing and physical

384 Woods Hole Rd

Woods Hole MA 02543 508-548-8700 x 2306 mbartlett@usgs.gov 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 2017 NC Lidar 2022 Kathryn Weber U.S. Geological Survey mailing and physical

384 Woods Hole Rd

Woods Hole MA 02543 508-548-8700 kweber@usgs.gov 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). 2022 Marie K. Bartlett U.S. Geological Survey mailing and physical

384 Woods Hole Rd

Woods Hole MA 02543 508-548-8700 x 2306 mbartlett@usgs.gov The metadata title was modified to move the location name to the beginning of the title to account for the alphabetical listing of the individual records when ScienceBase migrates the data release to a new platform and "flattens" the data release structure (20260302). 20260302 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Vector String 7 Universal Transverse Mercator 17 0.9996 -81.0 0.0 500000.0 0.0 coordinate pair 0.6096 0.6096 meters WGS_1984 WGS_84 6378137.0 298.257223563 NCwest_shoreline_2017 This dataset includes polyline shoreline for 2017 extracted from lidar data, for the North Carolina coastal region extending from Cape Fear to the South Carolina border. U.S. Geological Survey (USGS) FID Internal feature number. Esri Sequential unique whole numbers that are automatically generated. Shape Feature geometry. Esri Feature geometry. This shoreline is a polyline shapefile. Date_ Date of lidar survey from which the shoreline was extracted. 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. USGS 3.519 9.946 meters Source Agency that provided shoreline feature or the data source used (e.g. lidar) to digitize shoreline feature. USGS USGS USGS provided the shoreline feature or the data source used to digitize shoreline feature. USGS Source_b Method of deriving shoreline feature, if known. USGS Lidar Shoreline extraction from lidar USGS Year_ Four-digit year of shoreline. USGS 2017 Year of lidar survey USGS Shape_Leng Length of feature in meter units (WGS 1984 UTM Zone 17N) Esri 687.121 16497.820 meters Type The vertical shoreline reference used for shoreline extraction. USGS MHW Mean high water - a datum-based elevation reference USGS The entity and attribute information provided here describes the tabular data associated with the dataset. Please review the individual attribute descriptions for detailed information. U.S. Geological Survey U.S. Geological Survey USGS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov The dataset contains the polyline shapefile of the 2017 North Carolina lidar shoreline used to calculate long and short-term rates of change (NCwest_shoreline_2017.shp and other shapefile components), browse graphic (NCwest_shoreline_2017_browse.PNG), and the FGDC CSDGM metadata in XML format. 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. Shapefile ArcGIS 10.7.1 Esri polyline shapefile 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. 0.3 https://doi.org/10.5066/P9HYNUNV https://www.sciencebase.gov/catalog/file/get/64de6fe0d34e5f6cd55350c8 https://www.sciencebase.gov/catalog/item/64de6fe0d34e5f6cd55350c8 The first link is to the USGS publication page, the second link downloads all the data on the landing page, and the third link is to the dataset landing page. none 20260302 Marie K. Bartlett U.S. Geological Survey mailing and physical

384 Woods Hole Rd

Woods Hole MA 02543-1598 USA 508-548-8700 x2306 whsc_data_contact@usgs.gov The metadata contact email address is a generic address in the event the person is no longer with USGS. FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998