This data release consists of the estimated extent of inundation due to sea level change for the U.S. national coastal parks of the continental United States, Alaska, Hawaii, Puerto Rico, U.S. Virgin Islands, American Samoa, and Guam. The data and inundation results enable coastal flooding analysis and display at high resolution for 118 parks.

The estimated inundation extent was achieved by utilizing a modified bathtub approach as developed by the Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC) (Allen et al., 2010). The NOAA methodology “attempts to account for local and regional tidal variability and hydrological connectivity”. Sea level change polygon extents consist of 4 model run scenarios. The maps are based on Representative Concentration Pathways (RCPs), which are four greenhouse gas concentration trajectories. Two RCPs were chosen for this study, a moderate RCP4.5 and the most extreme RCP8.5. Each RCP was projected to the years 2050 and 2100.

Other data available in this series includes low-lying areas, defined by NOAA as “hydrologically "unconnected" areas that may flood”; the DEM used to model the inundation; and USGS DEMs for selected park units. The estimated extents and model DEM are available in ArcGIS personal geodatabase format. The USGS DEMs are available in geoTIFF format. The extents and model DEM have a UTM projection and NAD83 (2011) datum. The USGS DEMs have a geographic projection, NAD83 horizontal datum, and NAVD88 vertical datum unless noted otherwise. With questions, please contact Dr. Rebecca Beavers, Coastal Geology and Coastal Adaptation to Climate Change Coordinator, National Park Service, rebecca_beavers@nps.gov, 303-987-6945.

Caffrey, M., L. Lestak, W. Manley, and A. Forget, 2015, Estimated Extent of Coastal Flooding due to Sea Level Change and Storm Surge for 118 U.S. National Parks: NPS NRSS, University of Colorado at Boulder, digital media.