Matching Mean Sea Level Rise Projections to Local Elevation Datums

Abstract

A method is presented to consistently tie future mean sea level rise (MSLR) scenario projections to local geodetic and tidal datums. This extends the U.S. Army Corps of Engineer (USACE) guidance for incorporating the effects of future MSLR into coastal projects. While USACE relies on the National Oceanic and Atmospheric Administration (NOAA) 19-year National Tidal Datum Epoch (NTDE) for its datum relationships, the approach proposed herein generalizes this guidance by choosing the appropriate 19-year epoch centered on the start year of the MSLR scenario under consideration. The procedure takes into account the local annual sea level variability, which confounds the matching to any given single year while generalizing and preserving the 19-year averaging long used by NOAA to calculate the NTDE. Examples of the MSLR scenario matching procedure are given using actual data and projections for La Jolla, California, and Sewells Point (Hampton Roads), Virginia.