Identifying Roads to Be Inundated due to Relative Sea Level Rise (RSLR):
A Case Study in Annapolis Maryland
Abstract
Over the last century, relative sea level has risen by more than 1 ft in
Annapolis, Maryland. The rise in sea level has resulted in frequent
flooding in the City of Annapolis. According to National Oceanic and
Atmospheric Administration (NOAA), Annapolis has experienced a 925%
increase in flooding days over the past 50 years. This flooding is
directly affecting roadway transportation in Annapolis in terms of
traffic disruptions, which may result in disconnected mobility among
communities, road accidents and travel time delays, just to name a few.
This study proposes a general modeling framework to identify roadway
segments that are most likely to be flooded and by what depth, due to
relative sea level rise and employs the model in the coastal area of
Annapolis. To do this, roadway and bridge elevations extracted from
LiDAR DEM and DSM respectively, were compared with the annual exceedance
probability tide levels provided by NOAA. Roadway segment elevations
below the selected tide levels (1%, 10%, and 99%) are considered to
be inundated by 100-year, 10-year and 1-year sea level respectively.
Results suggest that, out of 36 roadways (excluding local roads)
examined, one minor arterial roadway segment may be flooded by a depth
ranging from 0.075 inches to 7.22 inches, at a 99% tide level of 2.17
ft (0.66 m). Three minor arterial and one major collector roadway
segments may be flooded by a depth ranging from 0.1 inches to 27.3
inches (2.27 ft), at a 10% tide level of 3.84 ft (1.17 m). Three minor
arterial, four major collector, and two minor collector roadway segments
may be flooded by a depth ranging from 0.002 inches to 52 inches (4.4
ft) at a 1% tide level of 5.97 ft (1.82 m). For the city’s
transportation network to become more resilient against sea-level rise,
these roadway segments should be prioritized for future capital
investment in response to seal level rise.