Joseph F. Terrano Kathryn E. Smith James G. Flocks 20160125 vector digital data (Polyline) U.S. Geological Survey Data Release doi:10.5066/F7XS5SGM St. Petersburg, FL U.S. Geological Survey https://doi.org/10.5066/F7XS5SGM Shorelines were derived from a U.S. Geological Survey topographic lidar survey that was conducted on January 16-18, 2014 over Breton Island, Louisiana and released under USGS field activity number 14LGC01. Quantum Spatial was contracted by the USGS to collect and process these data. This dataset contains vectorized shorelines created from data acquired from Breton Island, Louisiana. Shorelines were vectorized in ArcMap 10.2.2 so they could be used for area and shoreline change analysis, using the Digital Shoreline Analysis System (DSAS) version 4.0. Shoreline data are considered a crucial element in performing change analysis for erosion and accretion studies and for tracking shoreline movement over time. Lidar data were acquired to document the short and long-term changes of several barrier island systems in Louisiana. Digitized shorelines created from the Lidar data provide an accurate and measurable change in shape, area, and shoreline movement over short and long-term periods. 20140116 20140118 ground condition Complete None planned -89.183286 -89.170248 29.497416 29.473486 USGS Metadata Identifier USGS:9934c4cd-790a-44d4-95b5-f66a9b9dc3e4 None Lidar Coastal Shoreline data Shoreline Shoreline map Vectorization Mean High Water ISO 19115 Topic Category Oceans Elevation Environment Boundaries GeoscientificInformation Marine Realms Information Bank (MRIB) Keywords mapping shore shoreline erosion shoreline accretion barrier island migration USGS Thesaurus coastal processes erosion shoreline accretion barrier island migration None LA Breton Island Gulf of Mexico Louisiana USA None 2014 None The U.S. Geological Survey requests to be acknowledged as originator of the data in future products or derivative research. U.S. Geological Survey Joseph F. Terrano Researcher 1 mailing and physical

600 4th Street South

St. Petersburg Florida 33701 US (727) 502-8047 (727) 502-8001 jterrano@usgs.gov Monday through Friday, 9:00 a.m. to 5:00 p.m., Eastern Standard Time Funds for this report are part of project funds for the Louisiana Outer Coast Early Restoration Project, obtained by the natural resource trustees for the Deepwater Horizon Oil Spill, pursuant to the Framework for Early Restoration Addressing Injuries Resulting from the Deepwater Horizon Oil Spill executed April 20, 2011. USFWS is the project lead for the North Breton Island Barrier Island Restoration project. Acknowledgment of the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices. Sharing of new data layers developed directly from these data would also be appreciated by the U.S. Geological Survey staff. Users should be aware that comparisons with other datasets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photointerpretation, mapping conventions, and digital processes over time. These data are not legal documents and are not to be used as such. Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.2.2.3552 Martinez, L., O’Brien, S., Bethel, M., Penland, S., and Kulp, M. 2009 http://lacoast.gov/reports/project/3890772~1.pdf Plant, N.G., and Flocks, J.G. 2014 http://walrus.wr.usgs.gov/infobank/p/p0114la/html/p-01-14-la.nav.html Morton, R.A., Miller, T.L., and Moore, L.J. 2008 https://pubs.usgs.gov/of/2004/1043/ Vectorized shorelines were checked to ensure they were one continuous line. Dangles (or extra line segments) were removed, as necessary. The shorelines were split into foreshore and backshore, based on a visual assessment. Shorelines that did not represent the main shoreline of Breton Island, such as the Chandeleur Islands or the Mississippi River Delta were removed. To ensure accuracy, edited shorelines were compared to those shown on Breton Island, LA from other analysis years, as a method for maintaining consistency between which islands were removed from each of the shoreline datasets. U.S. Geological Survey 2014 remote-sensing data http://walrus.wr.usgs.gov/infobank/p/p0114la/html/p-01-14-la.nav.html 1500 Online 20140116 20140118 ground condition USGS Activity 14LGC01 (P-01-14-LA) Lidar-derived elevations were used to identify the mean high water (MHW) location for shoreline delineation. A topographic lidar survey was conducted in January 2014 over Breton Island, Louisiana. Lidar acquisition was prioritized to coincide with the lowest tide possible. Water clarity was also assessed and deemed acceptable prior to acquisition flights. The Breton Island lidar project called for the planning, acquisition, processing, and derivative products of topobathymetric lidar data, to be collected at a nominal pulse spacing (NPS) of 0.5-0.45 meters (4-5 pts/square meter). The data are projected to Universal Transverse Mercator (UTM), Zone 16, North American Datum (NAD) 1983, meters (m) coordinates. To vectorize the shorelines, the lidar Digital Elevation Model (DEM) data were added to ArcMap 10.2.2 and the symbology of the map was changed to classify the image into two elevation classes at 0.23 meters, delineating the location of the average mean high water (MHW) shoreline for the Breton Island area. The MHW elevation was determined by tide gauge measurements and is reported in Morton and others (2004). The two-class raster was then examined against aerial imagery and it was determined that this elevation provided a good approximation of the MHW shoreline via visual inspection of the wet/dry sand line. After the value of 0.23 m was chosen, the ArcMap tool "Contour List" was used to create a shoreline. To remove any sharp edges from the shoreline, the ArcMap tool "Smooth Line" was used. Using ArcMap’s “Edit” tool, any extra lines, overlapping lines, and remaining sharp angle lines were removed. If needed, some areas were hand digitized to ensure they matched the lidar data that were classified to 0.23 m. After the shoreline was edited, it was checked for any remaining errors using ArcMap 10.2.2 "Create Topology" tool. Five rules were added to ensure that the shorelines were matching up correctly. The five rules are that the shorelines must not have dangles, must not intersect (line), must not overlap (line), must not self intersect (line), and must not self-overlap (line). Next, using the “Validate Topology” tool, errors were flagged on the shoreline shapefile and fixed accordingly to ensure that the shoreline was continuous and free of errors. Shorelines were then split at the northern most point and the southern most point to get a foreshore and backshore shoreline. Added "UNCERTAINT" (double), "DATE_" (Text/10), "Shoreline_" (Text/20), and "Year" (Text/10) fields. 20150601 U.S. Geological Survey Joseph Terrano mailing and physical

600 4th Street South

St. Petersburg Florida 33701 US (727) 502-8047 (727) 502-8001 jterrano@usgs.gov Monday through Friday, 9:00 a.m. to 5:00 p.m., Eastern Standard Time Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. 20170313 U.S. Geological Survey Alan O. Allwardt Contractor -- Information Specialist mailing and physical address

2885 Mission Street

Santa Cruz CA 95060 831-460-7551 831-427-4748 aallwardt@usgs.gov Added keywords section with USGS persistent identifier as theme keyword. 20201013 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 1334 Universal Transverse Mercator 16 coordinate pair 0.6096 0.6096 meter D North American 1983 GRS 1980 6378137.0 298.257222101 Breton_Island_2014_Shoreline Shapefile USGS Shape Feature geometry ESRI Coordinates defining the features OBJECTID Automatically assigned values used to identify features. ESRI 1 140 Shape_Leng Length of feature in internal units. Esri 0.003124 1447.998835 UNCERTAINT A value representing the error associated with the imagery type that is used in the Digital Shoreline Analysis System (DSAS) statistical computations. USGS 1.9 Uncertainty of the shoreline position USGS DATE_ Date imagery was collected for Breton Island using the mm/dd/yyyy format. Imagery dates for data not representing Breton Island were excluded. USGS Date using the mm/dd/yyyy format Shoreline_ Shoreline classification used to separate foreshore and backshore shorelines. USGS Shorelines classified as "Fore" for foreshore and "Back" for backshore shorelines. Year 4-digit year in which the imagery was collected. USGS Single year in the YYYY format U.S. Geological Survey James Flocks mailing and physical

600 4th Street South

St. Petersburg Florida 33701 US (727) 502-8012 (727) 502-8001 Monday through Friday, 9:00 a.m. to 5:00 p.m., Eastern Standard Time All of this report is available online. Breton_Island_2014_Shoreline.shp This digital publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. ArcGIS Shapefile Shapefile containing 2014 vectorized shoreline for Breton Island, LA. https://coastal.er.usgs.gov/data-release/doi-F7XS5SGM/data/shapefiles/shorelines.zip None 20201013 U.S. Geological Survey Joseph Terrano mailing and physical

600 4th Street South

St. Petersburg Florida 33701 US (727) 502-8047 (727) 502-8001 jterrano@usgs.gov Monday through Friday, 9:00 a.m. to 5:00 p.m., Eastern Standard Time FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 local time Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of the data in future products or derivative research.