dataset NOAA Office for Coastal Management843-740-12022234 South Hobson AvenueCharlestonSC29405-2413coastal.info@noaa.gov 20230324 ArcGIS Metadata 1.0 NOAA Office for Coastal Management843-740-12022234 South Hobson Ave.CharlestonSC29405-2413coastal.info@noaa.govThis data may be downloaded at: http://www.csc.noaa.gov/slrhttps://www.coast.noaa.gov/slrhttps://coast.noaa.gov/digitalcoast/tools/slrhttps://coast.noaa.gov/slrdatahttps://www.coast.noaa.govFile Geodatabase Raster Dataset NOAA Office for Coastal Management: Coastal Flood Threshold Inundation Extent for Moderate High Tide Flooding 2012-01-01T00:00:00Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Office for Coastal Management (OCM)NOAA's Ocean Service, Office for Coastal Management (OCM)Charleston, SC<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>These data depict the potential inundation extent of coastal areas resulting from National Weather Service issued Coastal Flood Advisories. The High Tide Flooding areas are defined at monitored tide stations and are referenced to the MHHW tidal datum. The process used to produce the data can be described as a modified bathtub approach that attempts to account for both local/regional tidal variability. The process uses either two or three source datasets depending on geographic location to derive the final inundation rasters: the Digital Elevation Model (DEM) of the area, a tidal surface model that represents spatial tidal variability, and an interpolated threshold surface if there is significant difference between flooding thresholds between varying geographic areas. The tidal model is created using the NOAA National Geodetic Survey's VDATUM datum transformation software (http://vdatum.noaa.gov) in conjunction with spatial interpolation/extrapolation methods and represents the MHHW tidal datum in orthometric values (North American Vertical Datum of 1988).The interpolated threshold surface is created using a National Ocean Service mathematical formula derived from tide stations across the United States. The methods used to produce these data does not account for erosion, subsidence, or any future changes in an area's hydrodynamics. It is simply a method to derive data in order to visualize the potential scale and extent, not exact location, of inundation from High Tide Flooding events.</SPAN></P><P><SPAN>These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer depicting potential sea level rise and its associated impacts on the nation's coastal areas. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at sea level rise (slr) and coastal flooding impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses. Data and maps provided can be used at several scales to help gauge trends and prioritize actions for different scenarios. The Sea Level Rise and Coastal Flooding Impacts Viewer may be accessed at: https://www.coast.noaa.gov/slr </SPAN></P></DIV></DIV></DIV>The purpose of these data is to show the potential inundation extent caused by tide levels exceeding National Ocean Service defined flooding thresholds. Acknowledgment of the NOAA Office for Coastal Management as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices for data source is expected.NOAA Office for Coastal Management843-740-12022234 South Hobson Ave.CharlestonSC29405-2413coastal.info@noaa.govUnited StatesISO 19115 Topic CategoryclimatologyMeteorologyAtmosphereBathymetry/Topographysea level riseShorelineinundationfloodingelevationenvironmentoceansclimatologyMeteorologyAtmosphereBathymetry/Topographysea level riseShorelineinundationfloodingelevationenvironmentoceansUnited States<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>These data illustrate the scale of potential flooding, not the exact location, and do not account for erosion, subsidence, or future construction. Inundation is shown as it may appear during Coastal Flood Advisory conditions. These data should be used only as a screening-level tool for management decisions. As with all remotely sensed data, all features should be verified with a site visit. The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.</SPAN></P></DIV></DIV></DIV> Any conclusions drawn from the analysis of this information are not the responsibility of the Office for Coastal Management or its partners. A detailed methodology for producing these data can be found via the following url: https://coast.noaa.gov/data/digitalcoast/pdf/slr-flood-frequency-methods.pdf Microsoft Windows 10 Version 10.0 (Build 19045) ; Esri ArcGIS 13.0.2.360561-87.895000-79.45298831.11043324.279169The dataset is derived from the most recent elevation, coastal flood thresholds provided by WFO's, and VDATUM data available at date of processing.2012-01-01T00:00:002016-01-01T00:00:00 Standard methods for determining inundation were used. The vertical accuracy of these data is dependent on the source elevation data and the error associated with vertical datum conversions within NOAA's VDatum software. The Flood Frequency inundation extent areas currently shown in the NOAA CSC Sea Level Rise and Coastal Flooding Impacts Viewer. The current status of areas of coverage for the tool can be accessed at: http://www.csc.noaa.gov/slr The digital elevation model (DEM) of an area serves as one of two source datasets used to derive inundation outputs.NOAA OCM Digital Elevation ModelsCSC DEMs2016NOAA Office for Coastal Managementhttps://www.coast.noaa.gov/slrThe dataset is derived from the most recent elevation available at date of processing. The tidal conversion surface of an area serves as one of two source datasets used to create the inundation outputs and is derived from NOAA National Geodetic Survey's VDATUM software. NOAA OCM VDATUM Tidal Surface ModelsOCM VDATUM Tidal Surfaces2016NOAA Office for Coastal Managementhttp://vdatum.noaa.govThe dataset is derived from the most recent VDATUM data available at date of processing.The GeoPlan Center downloaded the raster data layers for each threshold (minor, moderate, major) from NOAA: https://coast.noaa.gov/htdata/Inundation/NOS_Mapping/NOS_HTF_2022.zip The individual rasters layers were projected to EPSG 4087 and then mosaicked together to form one statewide layer. No data values were reclassified to zeros. The process to derive the inundation rasters is as follows: 1. A tidal surface is generated using NOAA VDATUM tool and various spatial interpolation/extrapolation routines, dependent upon the area being mapped. The surface generated represents the spatial variability of offsets between MLLW, a tidal datum and NAVD88, an orthometric datum. 2. Using the DEM and the tidal surface, raster calculations are made using ArcGIS Spatial Analyst Raster Calculation tool to generate one 8-bit single value raster representing the extent of inundation. 3. If necessary, an additional flood threshold surface is created using spatial interpolation techniques to capture the variability between flooding thresholds within large geographic locations. This interpolated threshold surface is then added to the MLLW VDatum tidal surface to create a total water surface layer referenced to the MLL tidal datum. The total water surface would then be used with the DEM in calculating the final flood threshold layer. 2016-01-01T00:00:00OCM DEMsOCM VDATUM Tidal Surfacesexternal3ff9e4922d4a5e7bea1ecf68c77ba4ea33ebf90fNOAA Office for Coastal Management843-740-12022234 South Hobson AvenueCharlestonSC29405-2413coastal.info@noaa.govTrueNOAA Office for Coastal Management EPSG6.12(9.2.0) NOAA_HTF_MODERATETable2Value Attribute TableNOAAOBJECTIDOBJECTIDOID400Internal feature number.EsriSequential unique whole numbers that are automatically generated.ValueValueInteger400NOAAIndicates whether the area is flooded under moderate HTF threshold0Not floodedGeoPlan1FloodedNOAACountCountDouble800Number of cells corresponding to the value of flooded or not floodedGeoPlan 1.0 002 1500000005000