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 called the Sea Level Rise and Coastal Flooding Impacts Viewer. It depicts 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 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://coast.noaa.gov/slr.

This metadata record describes the Marsh Migration data displayed in the SLR Viewer. These data represent the potential distribution of each wetland type based on their elevation and how frequently they may be inundated under potential future SLR scenarios, from 0 to 10ft of SLR. As sea level rises, higher elevations will become more frequently inundated, allowing for marsh migration landward. At the same time, some lower-lying areas will be so often inundated that the marshes will no longer be able to thrive, becoming lost to open water. These data are based on the assumption that specific wetland types exist within an established tidal elevation range, based on an accepted understanding of what types of vegetation can exist given varying frequency and time of inundation, as well as salinity impacts from such inundation.

The data were created using the NOAA OCM Coastal Change Analysis Program (CCAP) land cover data, the SLR Viewer's digital elevation models, and NOAA VDatum tidal surfaces.

The data are available in 0.5ft increments of net sea level change, from 0 to 10ft. To determine the appropriate level, the user must identify a SLR scenario and an applicable accretion rate for the area of interest. The easiest way to do this is to go into the SLR Viewer's Marsh Migration tab; select a location, SLR scenario, and timeframe; and identify the closest available 0.5ft increment to what the viewer shows. For more information, see the tutorial at https://coast.noaa.gov/elearning/marshmigration/.

Data are available for download at https://coast.noaa.gov/htdata/raster1/landcover/bulkdownload/slr_wetland/.