This layer is sourced from www.horrycounty.org.

The HVA tool evaluates coastal hazard vulnerability from four components: 1.) Storm surge, 2.) Shoreline change rate (erosion or accretion), 3.) Flooding, and 4.) Social/economic vulnerability (SoVI®). The final products are vulnerability indices on a scale of 1 to 5, with 1 being the least risk, and 5 being the most risk. Storm surge data is based on the SLOSH (Sea, Lake and Overland Surges from Hurricanes) model, which was developed by the NOAA’s National Weather Service. SLOSH produces MEOWs (Maximum Envelope of Water) and MOMs (Maximum of MEOWs). The MEOW is a composite of many hypothetic model runs, with identical hurricane category, speed, and direction, but different landfalls. The maximum value for each grid is plotted. The MOMs (Maximum of MEOWs) is a composite of MEOWs for each category hurricane, plotting the maximum surge for each category. The MOM (AGL) data was used for the Charleston Harbor basin. SLOSH data can be obtained here after getting a password: https://slosh.nws.noaa.gov/sdp/download.phpGo here to obtain the password: http://140.90.8.37/sloshPub/disclaim.php.The South Carolina Department of Health and Environmental Control’s Office of Ocean and Coastal Resource Management (DHEC-OCRM) is the source for the shoreline change data. The shoreline change data is based on three time steps: 1800s, 1930s, and 2000s. The shoreline change analysis was completed using the AMBUR tool and the change rate utilized with the HVA tool was the End Point Rate (EPR). The shoreline change data can be downloaded through DHEC’s HVA web application, located here: http://www.scdhec.gov/HomeAndEnvironment/maps/GIS/Applications/Flood data is based on FEMA’s DFIRM (Digital Flood Insurance Rate Map) data. The DFIRMS used in this analysis were preliminary. The issue dates for these preliminary DFIRMS are as follows: Charleston County (12/21/2017), Beaufort County (6/30/2017), Jasper County (1/16/2017), Berkeley County (2/12/2016), Dorchester County (11/13/2015), Georgetown County (11/13/2015), and Horry County (9/11/2015). For Colleton County, no DFIRM data were available; therefore, the National Flood Hazard Layer (NFHL) was used, with a latest study effective data of 12/21/2017. Current available GIS datasets for each county can be found here: https://msc.fema.gov/portal/advanceSearch#searchresultsanchorThe social and economic vulnerability component was represented by the Social Vulnerability Index (SoVI®), which measures social vulnerability to environmental hazards. This index is produced by the University of South Carolina’s Hazards & Vulnerability Research Institute (USC HVRI). This is a relative index which incorporates 29 socioeconomic variables. DHEC-OCRM contracted with the Institute to run a SoVI® analysis specific to the study area of this project. This product can be downloaded through DHEC’s HVA web application, located here: http://www.scdhec.gov/HomeAndEnvironment/maps/GIS/Applications/. Additional information about SoVI® can be obtained from the USC website: http://artsandsciences.sc.edu/geog/hvri/sovi%C2%AE-0HVA produces several combination products including the following: 1.) Inundation (surge + flooding), 2.) Inundation + SoVI®, and 3.) Shoreline Change (rate, plus temporal and spatial variations). Users can examine each hazard component to see which has the most impact in any given area. Products can be viewed and downloaded through DHEC’s HVA web application, located here: http://www.scdhec.gov/HomeAndEnvironment/maps/GIS/Applications