Author(s): Qing-Ping Zou; Dongmei Xie; Jean Macrae; Anthony Mignone
Linked Author(s):
Keywords: Coastal flooding; Climate change; Sediment transport; Storm surge; Extreme storms
Abstract: According to a recent OECD report, the population subject to coastal flood risk could grow more than threefold to nearly 150 million people and the asset exposure could reach more than ten times current levels. The fully-coupled wave and ocean circulation model SWAN+ADCIRC was used to investigate the characteristics of coastal flooding and sediment transport during extreme events in the Northeastern USA in a changing climate. The model predictions for 2015 North American blizzard and 2007 Patriot’s Day storm compare well with the buoy, tidal gauge, water level staff and Lidar measurements. The tide-surge and wave interaction contributes significantly to the coastal flooding and sediment transport. The wave overtopping discharge at the Scituate Seawall in Massachusetts would almost double in a sea level rise scenario of 0.36 m by 2050 for a storm like the 2015 North American blizzard. Seawall crest needs to be raised by much more than sea level rise to cope with future storms since larger waves can arrive at the structure without breaking at larger water depth and the overtopping is dependent on both freeboard and wave height. The extent of coastal inundation at the Saco Bay, Maine would nearly double for a storm like the Patriot’s Day storm for a sea level rise of 1.0 m. The SWAN+ADCIRC hydrodynamic model is coupled with the sediment transport model. The predicted sediment transport pattern is closely correlated with the wave induced nearshore circulation at Saco Bay, Maine and altered significantly by the sea level rise.
Year: 2018