The Composite Risk Index Plus Sea Level Rise is generated by multiplying the SACS Composite Exposure Index by the SACS Combined Hazard Plus Sea Level Rise.  The Composite Exposure Index is created by summing three separate exposure indices which are weighted on a percentage basis:  Population and Infrastructure Index 60%, Environmental Cultural and Habitat 30%, and Social Vulnerability 10% (For the US Virgin Islands, 65% Population and Infrastructure data and 35% Environmental, Cultural and Habitat due to a lack of CDC Social Vulnerability data for the USVI). For additional information on the input datasets and methodology for the exposure indices, please reference the NACCS report, Appendix C, page 103: https://www.nad.usace.army.mil/Portals/40/docs/NACCS/NACCS_Appendix_C.pdf.The SACS Combined Hazard Index Plus Sea Level Rise depicts the percentage annual chance of a specific flood hazard, with an additional 3 ft. of sea level rise added to the flood surface elevation. The three flooding hazards depicted are the 10% annual chance flooding event, the 1% annual chance flooding event, and Category 5 Hurricane Maximum of Maximums. The 10% annual chance flooding is derived via a statistical analysis of tide gauges within the SACS study area, utilizing methodology developed by the USACE Engineering and Research Development Center (https://hdl.handle.net/11681/7353 or https://www.jcronline.org/doi/abs/10.2112/JCOASTRES-D-15-00031.1). The 10% annual chance flooding event raster index grid cells are assigned a value of 0.1. The 1% annual chance flooding are aggregated from FEMA’s National Flood Hazard Layer (https://www.fema.gov/national-flood-hazard-layer-nfhl) and raster index grid cells are assigned a value of 0.01. The Category 5 Maximum of Maximums hazard is pulled from NOAA’s storm surge SLOSH inundation data. These data are assigned a value of 0.001 to reflect the low probability of a Category 5 event. Three feet of sea level rise were added to the 10% and 1% annual chance flooding events for this hazard grid.The Composite Risk Index Plus Sea Level Rise grid resolution is 30 meters.This Tier 1 dataset is available for download here:Tier 1 Risk Assessment Download