Jin-Si R. Over Christopher R. Sherwood 20250611 1.0 vector and tabular digital data data release DOI:10.5066/P1PGG57F Woods Hole Coastal and Marine Science Center, Woods Hole, MA U.S. Geological Survey, Coastal and Marine Hazards and Resources Program Suggested citation: Over, J.R., and Sherwood, C.R., 2025, Supplemental data for Over and Sherwood (2025), Washover and washout locations and landcover classifications after hurricanes Florence, Dorian, Harvey, Ike, and Sandy in North Carolina, Texas, and New York: U.S. Geological Survey data release, https://doi.org/10.5066/P1PGG57F. These data are in direct support of the related jounral article: Over, J.R., and Sherwood, C.R., 2025, Outwash events inhibit vegetation recovery and prolong coastal vulnerability: Journal of Geophysical Research: Earth Surfaces, 130(6), e2024JF008162, https://doi.org/10.1029/2024JF008162. https://doi.org/10.5066/P1PGG57F https://www.sciencebase.gov/catalog/item/6705b0ccd34edddc3ed257c5 The data in this release support the journal article "Outwash events inhibit vegetation recovery and prolong coastal vulnerability". The research details the vegetation cover in washover and washout locations in North Carolina, Texas, and New York after hurricanes Florence, Dorian, Harvey, Ike, and Sandy. Aerial imagery observations indicate that washout sites create ponds and have a slower vegetation recovery to pre-storm levels than washover sites. Select imagery was classified into sand, water, and vegetation. To reproduce the results and figures in the paper, the extents of the analysis are provided in a GeoPackage organized by location, hurricane, and type of extent including washout, washover, and ponds. The results of the landcover classifications and the percent vegetation cover within the indiviudal extents are also provided. The geographic extents and results of the analysis allow others to reproduce our analyses. Landcover classifications support the study of vegetation recovery on coasts after storm events. These data are in direct support of the related journal article: Over, J.R., and Sherwood, C.R., 2025, Outwash events inhibit vegetation recovery and prolong coastal vulnerability: Journal of Geophysical Research: Earth Surfaces, 130(6), e2024JF008162, https://doi.org/10.1029/2024JF008162. 20080519 20100108 20130419 20170325 20170829 20171001 20181007 20190830 20190919 20200131 20191011 20200928 20220121 20221027 20220323 20230625 20241106 dates reflect time series of classified data. Complete Not planned -97.03555499 -72.87221368 40.73136616 27.86610871 None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Woods Hole Coastal and Marine Science Center WHCMSC classification hurricanes vegetation Sandy Dorian Florence Harvey Ike Marine Realms Information Bank (MRIB) keywords aerial and satellite photography USGS Thesaurus remote sensing coastal processes geospatial datasets ISO 19115 Topic Category geoscientificInformation oceans location USGS Metadata Identifier USGS:6705b0ccd34edddc3ed257c5 Common geographic areas United States New York North Carolina Texas Fire Island National Seashore Geographic Names Information System (GNIS) Bolivar Peninsula San Jose Island North Core Banks None Public domain (CC0-1.0) data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information. Jin-Si R. Over U.S. Geological Survey, Woods Hole Coastal and Marine Science Center Geographer mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 508-548-8700 x2297 jover@usgs.gov https://www.sciencebase.gov/catalog/file/get/6705b0ccd34edddc3ed257c5?name=ROI_Example.JPG&allowOpen=true An example of some washout regions of interest on North Core Banks. JPEG Arc Pro 3.0.0, Google Earth Pro Jin-Si R. Over Christopher R. Sherwood 2025 Journal of Geophysical Research: Earth Surfaces Volume 130, Issue 6 online American Geophysical Union This publication is the primary journal article these data support. https://doi.org/10.1029/2024JF008162 Jin-Si R. Over Andrew C. Ritchie Christine J. Kranenburg Jenna A. Brown Daniel D. Buscombe Tommy Noble Christopher R. Sherwood Jonathan A. Warrick Phillipe A. Wernette 2021 Open-File Report 2021-1039 Reston, VA U.S. Geological Survey This publication includes the general methodology for processing imagery in Metashape to produce DEMs and ortho products. https://doi.org/10.3133/ofr20211039 Christopher R. Sherwood Andrew C. Ritchie Jin-Si R. Over Christine J. Kranenburg Jonathan A. Warrick Jenna A. Brown C. Wayne Wright Alfredo L. Aretxabaleta Sara L. Zeigler Phillipe A. Wernette Daniel D. Buscombe Christie A. Hegermiller 2023 Journal of Geophysical Research: Earth Surface Volume 128, Issue 1 online American Geophysical Union This publication includes the general methodology for differencing elevation models to produce the Hurricane Dorian washout extents. https://doi.org/10.1029/2022JF006934 Chelby R. Kilheffer H. Brian Underwood Jordan Raphael Lindsay Ries Shannon Farrell Donald J. Leopold 2019 Ecology and Evolution Volume 9, Issue 20 online American Wiley Library This publication includes the Fire Island washover extents. https://doi.org/10.1002/ece3.5674 Russell G. Congalton Kass Green 2019 eBook Third Edition Boca Raton CRC Press This publication includes the basis for landcover classification statistics. https://doi.org/10.1201/9780429052729 Pontus Oloffson Giles M. Foody Martin Herold Stephen V. Stehman Curtis E. Woodcock Michael A. Wulder 2014 Remote Sensing of Enviornment Volume 148 online Elsevier This publication includes the basis for reporting classification accuracies. https://doi.org/10.1016/j.rse.2014.02.015 Classification accuracy is assessed using stratified (proportional to area of class) randomly generated points and a confusion matrix of unsupervised classification verses expert interpretation and higher resolution reference imagery. The number of random points was determined following Olofsson et al. (2014) based on an estimated user accuracy of 0.85 for all classes and a targeted standard overall error accuracy of 0.03. The Bolivar Peninsula site had 100 due to the smaller areas of study. All classifications have an overall accuracy assessment value greater than 0.80, which represents strong agreement between classification and reference data (Congalton and Green). See processing steps for accuracy values of the classifications. Classifications are limited to the polygon extents within the GeoPackage. A total of seven SQLite Data Feature Classes are in the GeoPackage that contain polygons categorized by date, hurricane, and location. North Core Banks (NCB) was classified at two scales, at the island platform level and within the washover (Hurricane Florence, n=89) and washout (Hurricane Dorian, n=83) extents over six imagery time steps. San Jose Island (SJI) was classified within washout (Hurricane Harvey, n=9) extents over five imagery time steps. The Bolivar Peninsula (BP) was classified within two washout (Hurricane Ike) regions of interest (ROI) over five imagery time steps. Fire Island (FI) was classified within washover (Hurricane Sandy, n=9) over three imagery time steps. Polygon boundaries of ponds, washout, and washover are based on human digitization and the accuracy scales on the resolution of the imagery and orthomosaics. True boundaries of the features are not expected to be off by more than 1 meter. Christine J Kranenburg Andrew C Ritchie Jenna A Brown Jin-Si R Over Christopher R Sherwood Jonathan Warrick Phillipe A Wernette 2022 JPEG and TXT dataset St. Petersburg Coastal and Marine Science Center U.S. Geological Survey https://doi.org/10.5066/P9RRSMOJ Digital 20191011 ground condition NCB Imagery 1 Used to delineate ponds on North Core Banks. Christine J Kranenburg Andrew C Ritchie Jenna A Brown Jin-Si R Over Christopher R Sherwood Jonathan Warrick Phillipe A Wernette 2022 JPEG and TXT dataset St. Petersburg Coastal and Marine Science Center U.S. Geological Survey https://doi.org/10.5066/P9M3NYWI https://cmgds.marine.usgs.gov/data-services/rscc/PrecisionAirborneCameraSystem/NC_OBX_20200928/ Digital 20200928 ground condition NCB Imagery 2 Used to delineate ponds on North Core Banks. Christine J Kranenburg Andrew C Ritchie Jenna A Brown Jin-Si R Over Christopher R Sherwood Jonathan Warrick Phillipe A Wernette 2024 JPEG and TXT dataset St. Petersburg Coastal and Marine Science Center U.S. Geological Survey https://doi.org/10.5066/P9M3NYWI https://cmgds.marine.usgs.gov/data-services/rscc/PrecisionAirborneCameraSystem/NC_OBX_20221020/ Digital 20221027 ground condition NCB Imagery 3 Used to delineate ponds on North Core Banks. Christine J Kranenburg Jenna A Brown Andrew C Ritchie Jin-Si R Over Daniel D. Buscombe Christopher R Sherwood Jonathan Warrick 2025 remote-sensing image, tabular digital data, vector digital data Pacific Coastal and Marine Science Center U.S. Geological Survey https://cmgds.marine.usgs.gov/data-services/rscc/PrecisionAirborneCameraSystem/NC_OBX_20241106-20241113/ https://doi.org/10.5066/P9M3NYWI Digital 20241106 20241113 ground condition NCB Imagery 4 Used to delineate ponds on North Core Banks Andrew C Ritchie Jin-Si R Over Christine J Kranenburg Jenna A Brown Daniel D. Buscombe Christopher R Sherwood Jonathan Warrick Phillipe A Wernette 2022 GeoTIFFs Pacific Coastal and Marine Science Center U.S. Geological Survey https://doi.org/10.5066/P9K3TWY7 Digital 20190830 20190912 ground condition NCB DEMs Used to delineate washout channels on North Core Banks GEOPACKAGE (Over_and_Sherwood_Supp_Extents.gpkg) NORTH CORE BANKS: Island platform region of interest (ROI) feature class (main.NCB_IslandPlatform_ROI) was created assess the landcover of the area adjacent to and affected by overwash and outwash events. The ROI aims to remove water (ocean) and back barrier marsh, which do not perform well in the unsupervised classification. The Hurricane Florence washover extents (main.NCB_Florence_Washover) were delineated by digitizing the extent of the interpreted sand class from an unsupervised classification (the number of classes is set to 3 with a minimum class size of 20 and sample interval of 10) of the 2018-10-07 orthomosaic (Ritchie and others, 2020) and clipping to the dune line in ArcPro (v 3.0.0). The Hurricane Dorian washout extents (main.NCB_Dorian_Washout) were delineated by the difference between NCB digital elevation models (Ritchie and others, 2022) from 2019-08-30 and 2019-09-12 following Sherwood and others (2023). Ponds in washout channels were hand digitized (main.NCB_Dorian_Washout_ponds) by J. Over, using the imagery from 2019-10-11, 2020-09-28, and 2022-10-20 (Kranenburg and others, 2022, 2023, 2024, 2025) that were turned into orthomosaics following Over and others (2021). SAN JOSE ISLAND: Individual washout channels were hand digitized by J. Over from 2017-08-29 georectified Google Earth imagery (main.SJI_Harvey_Washout). BOLIVAR PENINSULA: Hurricane Ike did not create individual washout channels, so two same sized ROI boxes were created next to each other on georectifed Google Earth Imagery to encompass the extent of washout that was replanted by the local government and an extent that was not remediated (main.BP_Ike_ROI). FIRE ISLAND: Washout extents were obtained from C. Kilheffer, and provided in main.FI_Sandy_Washover, to recreate the areas of vegetation recovery studied in Kilheffer and others (2019). NCB Imagery 1 NCB Imagery 2 NCB Imagery 3 NCB Imagery 4 NCB DEMs 2025 CLASSIFICATION DATA (Over_and_Sherwood_2025_Supp_VegetationCoverRaw.csv) Values are provided in the CSV by class, extent ID, and date. Percent cover is calculated by dividing the sum of the pixel count of vegetation classes by the pixel count sum of all classes and multiplied by 100. NORTH CORE BANKS: For each date (2018-10-08, 2019-08-30, 2019-10-11, 2020-09-28, 2022-10-20, 2024-11-06) an unsupervised classification was performed on the orthomosaic within the island platform ROI (main.NCB_IslandPlatform_ROI), the Hurricane Florence washover extents (main.NCB_Florence_Washover), and the Hurricane Dorian washout extents (main.NCB_Dorian_Washout) in ArcPro (v. 3.0.0) with 3 classes, a minimum class size of 20, and sample interval of 10. The three classes were visually interpreted into dense vegetation, sparse vegetation, and sand. Areas under the digitized ponds (when present), were assigned to water. A quality check was done with stratified random points using the Create Accuracy Assessment Points (n=200) and then the Compute Confusion Matrix Tool. For 2019-10-08 the overall accuracy (± 95% confidence interval (CI)) was 0.92±0.04, 2019-08-30 was 0.88±0.04, 2019-10-11 was 0.87±0.04, 2020-09-28 was 0.90±0.04, 2022-10-20 was 0.84±0.05, and 2024-11-06 was 0.88±0.04. SAN JOSE ISLAND: For each date (2017-03-25, 2017-08-29, 2020-10-31, 2022-03-23, and 2023-06-25) georectified Google Earth imagery was converted to a GeoTIFF. For each date an unsupervised classification was performed on the GeoTIFFs within the Hurricane Harvey washout extents (main.SJI_Harvey_Washout) in ArcPro (v. 3.0.0) with 3 classes, a minimum class size of 20, and sample interval of 10. The three classes were visually interpreted into vegetation, sand, and water. A quality check was done with stratified random points using the Create Accuracy Assessment Points (n=200) and then the Compute Confusion Matrix Tool. For 2017-03-25 the overall accuracy (± 95% CI) was 0.91±0.04, 2017-08-29 was 0.88±0.04, 2020-10-31 was 0.93±0.03, 2022-03-23 was 0.96±0.03, and 2023-06-25 was 0.94±0.04. Values are provided in the CSV by class, extent ID, and date. BOLIVAR PENINSULA: For each date (2008-05-19, 2010-01-08, 2013-04-19, 2018-01-02, and 2022-01-21) georectified Google Earth imagery was converted to a GeoTIFF. For each date an unsupervised classification was performed on the GeoTIFFs within the two Hurricane Ike ROIs (main.BP_Ike_ROI) in ArcPro (v. 3.0.0) with 3 classes, a minimum class size of 20, and sample interval of 10. The three classes were visually interpreted into vegetation, sand, and water. A quality check was done with random points using the Create Accuracy Assessment Points (n=100) and then the Compute Confusion Matrix Tool. For 2008-05-19 the overall accuracy (± 95% CI) was 0.92±0.05, 2010-01-08 was 0.91±0.05, 2013-04-19 was 0.96±0.04, 2018-01-02 was 0.97±0.03, and 2022-01-21 was 0.95±0.04. FIRE ISLAND: For each date (2017-10-01, 2019-09-19, and 2021-04-04) georectified Google Earth imagery was converted to a GeoTIFF. For each date an unsupervised classification was performed on the GeoTIFFs within the Hurricane Sandy washout extents (main.FI_Sandy_Washover) in ArcPro (v. 3.0.0) with 2 classes, a minimum class size of 20, and sample interval of 10. The two classes were visually interpreted into vegetation, and sand. A quality check was done with random points using the Create Accuracy Assessment Points (n=200) and then the Compute Confusion Matrix Tool. For 2017-10-01 the overall accuracy (± 95% CI) was 0.89±0.04, 2019-09-19 was 0.88±0.04, and 2021-04-04 was 0.89±0.04. 2025 Jin-Si R. Over U.S. Geological Survey, Woods Hole Coastal and Marine Science Center Geographer mailing and physical address

U.S. Geological Survey

384 Woods Hole Rd.

Woods Hole MA 02543-1598 508-548-8700 x2297 jover@usgs.gov Vector G-polygon 653 WGS 1984 Web Mercator Auxiliary Sphere 0.0 0.0 0.0 0.0 coordinate pair 0.6096 0.6096 meters D_WGS_1984 WGS84 6378137.0 298.257223563 Over_and_Sherwood_Supp_Extents.gpkg Table containing attribute information associated with the dataset; main.BP_Ike_ROI, main.FI_Sandy_Washover, main.NCB_Dorian_Washout, main.NCB_Dorian_Washout_Ponds, main.NCB_NCB_IslandPlatform_ROI, and main.SJI_Harvey_Washout. USGS OBJECTID Automatically generated non-repeating internal feature number. Esri 1 460 Shape Feature geometry Esri polygon A shape defined by one or more rings, where a ring is a path that starts and ends at the same point. Esri GIS dictionary Area_m2 Geodesic area of polygon. Esri 6 5,409,860 square meters Date Date in YYYYMMDD corresponding to the initial imagery or orthomosaic the polygon was digitized from (see larger work citation for a table of dates and imagery sources). A NaN occurs if polygon is not generated off of a specific date. Producer defined Character string. Location Abbreviated code of the geographic location of the polygons. Producer defined NCB North Core Banks Producer defined SJI San Jose Island Producer defined BP Bolivar Peninsula Producer defined FI Fire Island Producer defined Hurricane Name of the hurricane(s) associated with the polygon(s). If multiple hurricanes are associated, they are separated by a /. World Meteorological Organization Character string. Over_and_Sherwood_2025_Supp_VegetationCoverRaw.csv Table containing attribute information and classification data. USGS Unique_ID Generated non-repeating identification number. USGS 0 764 ID Identification Number for individual washout or washover extents in each Hurricane and location pair that repeats for multiple dates of analysis. NaN occurs in polygons that are not washout or washover extents. USGS 0 89 Area_m2 Geodesic area of polygon. Esri 46 5,409,860 square meters Date Date in YYYYMMDD corresponding to the imagery or orthomosaic the analysis was completed on (see journal Supporting Information) for a table of dates and imagery sources). Producer defined Character string. Location Abbreviated code of the geographic location of the analysis. Producer defined NCB North Core Banks Producer defined SJI San Jose Island Producer defined BP Bolivar Peninsula Producer defined FI Fire Island Producer defined Hurricane Name of the hurricane associated with the analysis. World Meteorological Organization Character string. Type The type of feature or location being analyzed (see process steps and larger work citation for more detail). Producer defined ROI A region of interest. Producer defined Washout A digitized washout feature. Producer defined Washover A digitized washover feature. Producer defined Dense_Vegetation Interpreted unsupervised landcover classification of vegetation with little to no clear patches between individual plants. A NaN value occurs if vegetation was not split between dense and sparse. Producer defined 0 9,853,569 pixels Sparse_Vegetation Interpreted unsupervised landcover classification of vegetation with clear patches between individual plants. A NaN value occurs if vegetation was not split between dense and sparse. Producer defined 0 6,380,229 Vegetation Interpreted unsupervised landcover classification of vegetation (may be the sum of the sparse and dense vegetation classes). Producer defined 0 16,028,076 pixels Sand Interpreted unsupervised landcover classification of sand or bare ground with the assumed substrate of sand. Producer defined 91 7,730,937 pixels Water Interpreted unsupervised landcover classification of water. Producer defined 0 2,618,180 pixels %_Cover The vegetation cover for each extent calculated by dividing the Vegetation class by the sum of the Vegetation, Sand, and Water classes multiplied by 100. Producer defined 0.00 88.97 percent The GeoPackage contains individual feature classes, labeled as main.Location_Hurricane_Type, that are being used as boundaries for the classification analysis. Location and Hurricane are in the attribute tables and Type includes Washout, Washover, Washout ponds, and ROI. The OBJECTID in the GeoPackage feature classes corresponds to the ID attribute in the csv. USGS U.S. Geological Survey - ScienceBase mailing and physical address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov The GeoPackage provides the extents to which hurricane outwash and overwash affected various coasts and are the geographic extent of the landcover classification results. These data support the journal article "Outwash events inhibit vegetation recovery and prolong coastal vulnerability". 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. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although these data have been processed successfully on a computer system at 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. 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. GeoPackage file; service definition file ArcPro 3.0.0 The GeoPackage file which has the seven feature classes. 32 https://www.sciencebase.gov/catalog/item/6705b0ccd34edddc3ed257c5 https://www.sciencebase.gov/catalog/file/get/6705b0ccd34edddc3ed257c5 https://doi.org/10.5066/P1PGG57F The first link in the list above is to the child page where files can be downloaded individually, the second link is to directly download all the data on the page, and the third link is to the doi to the main publication. CSV Exported from Excel Office 365 16.01 The CSV file contains raw classification data. 0.02 https://www.sciencebase.gov/catalog/item/6705b0ccd34edddc3ed257c5 https://www.sciencebase.gov/catalog/file/get/6705b0ccd34edddc3ed257c5 https://doi.org/10.5066/P1PGG57F The first link in the list above is to the child page where files can be downloaded individually, the second link is to directly download all the data on the page, and the third link is to the doi to the main publication. none The GeoPackage requires use of GIS software such as QGIS or ArcGIS 20250611 Jin-Si R. Over U.S. Geological Survey, Woods Hole Coastal and Marine Science Center Geographer mailing and physical

U.S. Geological Survey

384 Woods Hole Rd.

Woods Hole MA 02543-1598 508-548-8700 x2297 whsc_data_contact@usgs.gov The metadata contact email address is a generic address in the event the person is no longer with USGS. Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 local time