Elevation Uncertainty in Coastal Inundation Hazard Assessments

Best Practices for Elevation-Based Assessments of Sea-Level Rise and Coastal Flooding Exposure

“…Based on the concept of elevation contour line accuracy, a method has been developed (Gesch, 2012a(Gesch, , 2013 to determine the minimum contour interval, or in the present case, the minimum increment of water level increase that can be used to meet a specified confidence level. Using the minimum increment in an assessment ensures that the chosen study parameter (amount of SLR or flooding level) is truly supported by the DEM and is not too small given the inherent vertical uncertainty.…”

“…Overall, SLRI min and TL min are useful to determine what parameters can be effectively used in assessments, especially from a management perspective (Gesch, 2012a). When a specific DEM with a stated accuracy is available, SLRI min and TL min will be useful for determining what increments and planning horizons (given a SLR rate) will be allowable for high confidence results.…”