Curt D. Storlazzi Theresa A. Fregoso 2018 GeoTIFF data release DOI:10.5066/F7VD6XDB Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/F7VD6XDB https://www.sciencebase.gov/catalog/item/59ef8172e4b0220bbd98d40f Projected future wave-driven flooding depths on Roi-Namur Island on Kwajalein Atoll in the Republic of the Marshall Islands for a range of climate-change scenarios. This study utilized field data to calibrate oceanographic and hydrogeologic models, which were then used with climate-change and sea-level rise projections to explore the effects of sea-level rise and wave-driven flooding on atoll islands and their freshwater resources. The overall objective of this effort, due to the large uncertainty in future emissions (and thus climate change scenarios) that is largely irreducible, was to reduce risk and increase island resiliency by providing model simulations across a range of plausible future conditions. This effort focuses on Roi-Namur Island on Kwajalein Atoll in the Republic of the Marshall Islands (RMI). RMI is home to more than 1,100 low-lying islands on 29 atolls, yet the approach and findings presented in this study can serve as a proxy for atolls around the world, most of which have a similar morphology and structure, including on average, even lower land elevations, and are the home for numerous island nations and hundreds of thousands of people. The primary goal of this investigation was to determine the influence of climate change and sea-level rise on wave-driven flooding and the resulting impacts to infrastructure and freshwater resources on atoll islands. First, we mapped the morphology and benthic habitats of the atoll to determine the influence of spatially-varying bathymetric structure and hydrodynamic roughness on wave propagation over the coral reefs that make up the atoll. Second, we analyzed historic meteorologic and oceanographic data to provide historical context for the limited in-situ data and comparison to previous seawater overwash and flooding events. These data were then used to calibrate and validate physics-based, dynamically-downscaled numerical models to project future atmospheric and oceanic forcing for a range of climate-change scenarios. Third, we made in-situ observations to better understand how changes in meteorologic and oceanographic forcing controlled wave-driven water levels, seawater flooding of the island, and the resulting hydrogeologic response. We then used those data to calibrate and validate a physics-based, numerical hydrodynamic model of the island. The hydrodynamic model was used to forecast future wave-driven island overwash and seawater flooding for a range of climate-change and SLR scenarios. The data provided here are the seawater flooding depths for three Intergovernmental Panel on Climate Change (IPCC) AR5 climate-change scenarios: Representative Concentration Pathways (RCP)4.5 and RCP8.5, representing medium and high greenhouse concentration trajectory scenarios, respectively, and RCP8.5 plus icesheet collapse (RCP8.5i). The climate-change scenarios were incorporated into the model by increasing mean sea level based on the future sea-level rise and wave projections. The modeled time frame ranged from 2035 to 2105 at 10-yr time steps. These data accompany the following publication: Storlazzi, C.D., Gingerich, S.B., van Dongeren, A., Cheriton, O.M., Swarzenski, P.W., Quataert, E., Voss, C.I., Field D.W., Annamalai, H., Piniak G.A., McCall, R., 2018, Most atolls will be uninhabitable by the mid-21st century due to sea-level rise exacerbating wave-driven flooding, Science Advances, https://doi.org/10.1126/sciadv.aap9741. The U.S. Geological Survey (USGS), National Oceanographic and Atmospheric Administration (NOAA), Deltares, and University of Hawaii (UH) conducted a study to provide basic understanding and specific information on the impact of climate change and sea-level rise on Roi-Namur Island on Kwajalein Atoll in the Republic of the Marshall Islands, which is part of the Ronald Reagan Ballistic Missile Test Site. The primary goal of this joint investigation was to determine the influence of climate change and sea-level rise on wave-driven flooding and the resulting impacts to infrastructure and freshwater resources on atoll islands. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ESRI format, this metadata file may include some ESRI-specific terminology. 2018 publication date Complete Irregular 167.452484 167.483303 9.411218 9.389429 USGS Metadata Identifier USGS:59ef8172e4b0220bbd98d40f ISO 19115 Topic Category Elevation geoscientificInformation Data Categories for Marine Planning predictions USGS Thesaurus geospatial datasets floods mathematical modeling effects of climate change earth sciences Marine Realms Information Bank (MRIB) keywords coral reefs reef waves flooding coastal processes numerical modeling None U.S. Geological Survey USGS Coastal and Marine Geology Program CMGP Pacific Coastal and Marine Science Center PCMSC Geographic Names Information System (GNIS) Roi-Namur Kwajalein Marshall Islands None USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060-5792 US 831-427-4747 pcmsc_data@usgs.gov https://www.sciencebase.gov/catalog/file/get/59ef8172e4b0220bbd98d40f?name=RCP_85I_2105.jpg Wave-driven flood water depth for RCP scenario 85+ice sheet collapse, year 2105. JPEG Environment as of Metadata Creation: Microsoft Windows 10 Version 10.0.143 (Build 14393); ESRI ArcGIS 10.5.0 (Build 6491) Curt D. Storlazzi Stephen B. Gingerich Ap van Dongeren Olivia M. Cheriton Peter W. Swarzenski Ellen Quataert Clifford I. Voss Donald W. Field Hariharasubramanian Annamalai Greg A. Piniak Robert McCall 2018 Journal article Science Advances online American Academy for the Advancement of Science https://doi.org/10.1126/sciadv.aap9741 No formal attribute accuracy tests were conducted. No formal logical accuracy tests were conducted. Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. A formal accuracy assessment of the horizontal positional information in the data set has not been conducted. A formal accuracy assessment of the vertical positional information in the data set has not been conducted. Deltares 2017 xyz.csv Unpublished Unpublished model outputs 2035 2105 modeled projection dates of data points xyz file modeled xyz file used to create raster surface Convert xyz.csv file to points then a TIN. Convert TIN to Raster. Model Builder was used to batch convert 24 xyz.csv files to points using the ASCII 3D to feature class tool followed by the Create TIN tool. For the TIN, the height field was Z, with SF Type of Mass_points. Model Builder was used to batch convert TINS to rasters using the TIN to Raster tool. The output data type for the raster was FLOAT, the method LINEAR, and the Sampling Distance was CELLSIZE 0.5. xyz file 2016 Removed empty tag and corrected minor typo in metadata file. No data were changed. 20180629 Susan A Cochran U.S. Geological Survey, Pacific Coastal and Marine Science Center Geologist mailing and physical address

2885 Mission Street

Santa Cruz CA 95060-5792 USA (831) 460-7545 scochran@usgs.gov Corrected Point of Contact and Metadata Contact phone number prefix. No data were changed. 20180905 Susan A Cochran U.S. Geological Survey, Pacific Coastal and Marine Science Center mailing and physical

2885 Mission St.

Santa Cruz CA 95060 United States 831-460-7545 scochran@usgs.gov Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 20201019 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 Raster Pixel 4775 6740 Universal Transverse Mercator 58 0.9996 165.0 0.0 500000.0 0.0 row and column 0.5 0.5 Meter D_WGS_1984 WGS_1984 6378137.0 298.257223563 Mean Sea Level that was calculated using a temporary USGS water sensor located on a pier. See report for more detail. 0.01 meters Explicit elevation coordinate included with horizontal coordinates Water flood depth over island elevation. See report for more detail. U.S. Geological Survey - ScienceBase mailing and physical

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov These data are available in GeoTIFF format contained in a single zip file (Roi_Namur_RCP_surfaces.zip) which also includes CSDGM FGDC-compliant 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 on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. geoTIFF ArcGIS 10.5.0 Zip file contains the 24 different modeled scenarios for flood level depth and the associated metadata. WinZip 2040 https://www.sciencebase.gov/catalog/file/get/59ef8172e4b0220bbd98d40f?name=Roi_Namur_RCP_surfaces.zip https://doi.org/10.5066/F7VD6XDB Data can be downloaded using the Network Resource links. The first link begins a direct download of this particular dataset. The second link goes to a landing page for the data release. None. These data can be viewed with ArcGIS software. 20201019 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060-5792 US 831-427-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998