Meredith G. Kratzmann 20260622 1.0 vector digital data data release DOI:10.5066/P1JE2KSO 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/P1JE2KSO https://www.sciencebase.gov/catalog/item/69e2afc2b66b0195694c11e3 Meredith G. Kratzmann Amy S. Farris Kathryn M. Weber 2026 1.0 vector digital data data release DOI:10.5066/P1JE2KSO Reston, VA U.S. Geological Survey suggested citation: Kratzmann, M.G., Farris, A.S., and Weber, K.M., 2026, National Shoreline Change—A GIS compilation of vector shorelines and associated shoreline change data from the 1800s to the 2020s for the coast of Alabama: U.S. Geological Survey data release, https://doi.org/10.5066/P1JE2KSO. https://doi.org/10.5066/P1JE2KSO https://www.sciencebase.gov/catalog/item/69e2a7d5b66b0195694c1197 The U.S. Geological Survey (USGS) maintains shoreline positions for the United States coasts from various historical sources, such as aerial photographs or topographic surveys, and contemporary sources, such as lidar-point clouds and digital elevation models. Shorelines are compiled in a Geographic Information System (GIS) and analyzed in the USGS Digital Shoreline Analysis System (DSAS) software to calculate rates of change. Keeping a record of historical shoreline positions is an effective method to monitor change over time, enabling scientists to identify areas most susceptible to erosion or accretion. These data can help coastal managers understand which areas of the coast are vulnerable to change. The shoreline positions and shoreline change rates provide actionable information to homeowners, coastal communities, and managers of public and private properties to improve resiliency for coastal hazards. This dataset includes reference baseline segments used by the Digital Shoreline Analysis System (DSAS) to calculate rate-of-change statistics for the coast of Alabama. The baseline layer serves as the starting point for orthogonally-oriented transects generated by the DSAS application. The transects intersect each shoreline and establish measurement points used to calculate shoreline change rates. 2026 publication date Complete None planned -88.350587 -87.517445 30.278659 30.216387 ISO 19115 Topic Category oceans environment geoscientificInformation None Baseline Shoreline Change Digital Shoreline Analysis System DSAS U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Woods Hole Coastal and Marine Science Center WHCMSC USGS Thesaurus geospatial datasets coastal processes USGS Metadata Identifier USGS:69e2afc2b66b0195694c11e3 GNIS State of Alabama Dauphin Island Fort Morgan Alabama Gulf Shores None Gulf Coast Bon Secour National Wildlife Refuge United States of America North America No access constraints. Please see 'Distribution Information' for details. These data are marked with a Creative Commons CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. 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. U.S. Geological Survey Meredith G. Kratzmann mailing and physical

384 Woods Hole Road

Woods Hole MA 02543-1598 USA 508-548-8700 508-457-2310 mkratzmann@contractor.usgs.gov https://www.sciencebase.gov/catalog/file/get/69e2afc2b66b0195694c11e3?name=AL_baseline.png&allowOpen=true Map view of data. Yellow line indicates extent of the baseline for Alabama. PNG Microsoft Windows 11 Enterprise; Esri ArcGIS Pro 3.5.5 Rachel E. Henderson Amy S. Farris Meredith G. Kratzmann Marie K. Bartlett Ayhan Ergul John McAndrews Raison Cibaj Jessica L. Zichichi Emily A. Himmelstoss E. Robert Thieler 2026 publication software release version 6.1.177 Reston, VA U.S. Geological Survey Use the first link to access the publication page. The second link is to the current version of DSAS (v6.1). The third link directs to the DSAS project page. https://doi.org/10.5066/P1NHMJNC https://code.usgs.gov/cch/dsas https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-system-dsas The attributes in this layer are based on the requirements for use within DSAS. Each polyline has a unique identification attribute (DSAS_ID). This field is used by the DSAS to designate the alongshore order of baselines, if more than one baseline segment exists. This baseline file is complete and contains the baseline segment(s) used to cast transects along sections of the coastal region where shoreline position data were present. The baseline serves as a reference point for transects cast by DSAS. It does not correspond to any real-world feature. A baseline was constructed with respect to the time series of shoreline positions using standard editing tools in ArcGIS Pro v3.5.5. The offshore baseline was positioned to conform to the overall orientation of the shorelines. This was done so that the transects, which are generated by DSAS from the baseline, would intersect roughly perpendicular to the general trend of the shorelines. ID values were added to each segment in sequential order alongshore starting with 1. This and the following process steps were performed by Meredith G. Kratzmann. 2025 Meredith G. Kratzmann U.S. Geological Survey mailing and physical

384 Woods Hole Road

Woods Hole MA 02543-1598 USA 508-548-8700 508-457-2310 mkratzmann@contractor.usgs.gov The baseline shapefile was loaded into the Digital Shoreline Analysis System (DSAS) v6.1 software to perform rate calculations. 2026 The baseline shapefile was projected in ArcGIS Pro v3.5.5 > Geoprocessing > Data Management Tools > Projections and Transformations > Project. Parameters: Input Coordinate System - NAD_1983_2011_UTM_Zone_16N; Output Coordinate System - GCS_WGS_1984; transformation = WGS_1984_(ITRF08)_To_NAD_1983_2011. 2026 Vector String 4 0.0000001 0.0000001 Decimal degrees WGS_1984 WGS_1984 6378137.000000 298.257224 AL_baseline.shp Table containing attribute information associated with the data set for Alabama. U.S. Geological Survey FID Internal feature number used as a unique identifier of an object within a table primarily used in shapefiles. Esri Sequential unique whole numbers that are automatically generated. Shape Feature geometry. Esri Feature type. DSAS_ID Field required by the Digital Shoreline Analysis System (DSAS) software. DSAS uses this value to determine the ordering sequence of transects when the baseline feature contains multiple segments. Individual segments are numbered sequentially alongshore. U.S. Geological Survey 1 4 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 - GS 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 baselines used for the analysis of shoreline data (SHP and other shapefile components), browse graphic, and the FGDC CSDGM metadata. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Shapefile Esri ArcGIS Pro 3.5.5 Esri polyline shapefile (compressed to ZIP format) These files (.cpg, .dbf, .prj, .sbn, .sbx, .shp, .html, 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 HTML format. Transfer size is in MB. Unzip 0.012 https://doi.org/10.5066/P1JE2KSO https://www.sciencebase.gov/catalog/item/69e2afc2b66b0195694c11e3 https://www.sciencebase.gov/catalog/file/get/69e2afc2b66b0195694c11e3 The first link is to the USGS publication page, the second link is to the dataset page, and the third link downloads the data. None These data are available in a polyline shapefile format. The user must have software to read and process the data components of a shapefile. 20260622 Meredith G. Kratzmann U.S. Geological Survey mailing and physical

384 Woods Hole Road

Woods Hole MA 02543-1598 USA 508-548-8700 508-457-2310 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 local time