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During extreme storms, both wind‐driven changes in water levels and intense precipitation can contribute to flooding. Particularly on low‐lying coastal plains, storm‐driven flooding can cover large areas, resulting in major damage. To investigate the roles of rainfall and storm surge on coastal flooding, a coupled flow‐wave model (Delft3D‐SWAN) tha...
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The Humen Estuary, one of the largest outlets of the Pearl River, is a long and wide tidal channel with a considerable tidal flow every year. Storm surges, always superposing spring tide, travel from the estuary and endanger the safety of people living around the river. However, little research has quantified the relationship between the hydraulic...
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... The wind drag coefficient is defined as a function of wind speed, from C D = 0.00063 to 0.00723 for wind speeds of U = 0 to 100 ms −1 , respectively (default conditions) with an air density of = 1.2 kgm −3 . The model does not include precipitation or river flows, which can be important in shallow coastal regions (Rey et al. 2020); however, river flood peaks from hurricane rainfall events can occur days after the event (Brown et al. 2014), and the goal of the present study is to investigate water level changes from storm surge. ...
Hurricanes with high winds can generate strong ocean circulation, storm surges, and large surface waves that impact coastal regions. In 2018, Hurricane Florence crossed the narrow continental shelf and made landfall in Onslow Bay, North Carolina, USA, a 160 km curved embayment rimmed by a chain of barrier islands with inlets and narrow back-barrier lagoons. This storm had significant impacts to Bear Island, an undeveloped barrier island, including overwash and shoreline recession of the beach/dune system of up to 40 m. The objective of this study is to apply a flexible mesh numerical model to investigate wave generation by wind over the ocean, and the fine-scale response of flow and storm surge in shallow nearshore areas including inlets and back-barrier estuaries. The hydrodynamic conditions surrounding four different barrier island systems that received different hurricane wind and wave forcing relative to the cyclone eye are investigated. The highest total water levels around the barrier islands are driven by the combined tide, storm surge and waves, resulting in complex circulation patterns related to the network of shallow channels in the back-barrier environment.
Tropical cyclones, including hurricanes, have high winds that can generate strong ocean surface circulation and large surface waves and numerous hurricanes that form and propagate over the Atlantic Ocean interact with the continental shelf. Hurricane Frey et al. (2012) impacted the east coast of North America after moving across the narrow shelf and made landfall in Onslow Bay, North Carolina, USA. In contrast, Hurricane Isaias (2020) moved generally parallel to the continental shelf, making landfall in Onslow Bay along a very different track compared to Hurricane Florence. These hurricanes provide an opportunity to understand the waves generated by large storms that move across the open ocean to the coastal environment on the shelf. In this study, the coupled Delft3D-SWAN modelling system is applied to numerically simulate the wind and wave conditions during both Hurricane Florence and Hurricane Isaias. The simulations are analyzed to understand the source terms that control the generated and dissipation of the surface wave field. The model results for Hurricane Florence, indicated that the deep water terms (wind input, whitecapping and quadruplet wave interactions) governed wave action balance on the shelf and in Onslow Bay (10–100 m depths), with negligible contributions from the shallow water dissipation terms such as bottom friction. Hurricane Isaias followed the same trend, but with lower values corresponding to lower wind speeds and smaller wave heights. In addition, Hurricane Florence crossed the shelf and approached the bay from the open ocean with larger waves that were not limited by fetch. In contrast, since Hurricane Isaias followed the coast along the shelf, the wave conditions were fetch-limited on the west side of the track near the coast and not limited by fetch on the east side on the open shelf. The results of this study underscore how hurricanes with different tracks with respect to the orientation of the shelf and coast generate different wave fields and impact coastal environments in different ways.
This review focuses on recent advances in process-based numerical models of the impact of extreme storms on sandy coasts. Driven by larger-scale models of meteorology and hydrodynamics, these models simulate morphodynamics across the Sallenger storm-impact scale, including swash, collision, overwash, and inundation. Models are becoming both wider (as more processes are added) and deeper (as detailed physics replaces earlier parameterizations). Algorithms for wave-induced flows and sediment transport under shoaling waves are among the recent developments. Community and open-source models have become the norm. Observations of initial conditions (topography, land cover, and sediment characteristics) have become more detailed, and improvements in tropical cyclone and wave models provide forcing (winds, waves, surge, and upland flow) that is better resolved and more accurate, yielding commensurate improvements in model skill. We foresee that future storm-impact models will increasingly resolve individual waves, apply data assimilation, and be used in ensemble modeling modes to predict uncertainties.
Expected final online publication date for the Annual Review of Marine Science, Volume 14 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
