Coastal Flooding Today, Tomorrow, and the Next Ten Years in East Coast
U.S. Cities
Abstract
When will a particular city on the Eastern Seaboard have a 70% chance
of flooding at least one hour on at least 70 days of the year? This
jam-packed question drives this study, as coastal flooding is becoming
increasingly frequent in many East Coast U.S. cities. The frequency of
floods that were once categorized as high tide or “nuisance” flooding
is rapidly increasing, and many events are escalating to the moderate
and major/severe flooding thresholds, putting life and property at risk.
This study focuses on flooding events prone to causing property damage
and hazardous conditions to make improvements for the subseasonal and
seasonal outlooks that are most impactful. A number of East Coast cities
are employed as case studies, such as Key West, FL, Charleston, SC, and
Annapolis, MD, to analyze current and projected flooding rates. The
spatial extent of flooding is considered by using high-resolution
topographical data in combination with National Ocean Service tidal
datums. NOAA sea level rise scenarios are used to determine the probable
time period at which a portion of each city will be experiencing
flooding for at least one hour per day frequently throughout the year.
Additionally, tide gauge data from the case study cities is decomposed
to understand which physical components are contributing to the regional
coastal flooding on timescales from subseasonal to seasonal and beyond.