Assessing Compound Flooding From Landfalling Tropical Cyclones on the North Carolina Coast
Assessing Compound Flooding From Landfalling Tropical Cyclones on the North Carolina Coast
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DOI：
10.1029/2019wr026788
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发表时间：
2020-04-01
影响因子：
5.4
通讯作者：
Smith, James
中科院分区：
文献类型：
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作者：
Gori, Avantika;Lin, Ning;Smith, James
由于风力驱动的风暴潮和热带气旋降雨的相互作用，热带气旋（TC）事件是复合洪水的主要驱动因素。传统上，沿海洪水风险模型只考虑了浪涌洪水，即使它是众所周知的，径流的作用是至关重要的。对于能够产生显著复合的TC事件类型以及海岸现场条件如何影响风暴潮和径流相互作用的程度，了解有限。本研究调查了一套历史TC附近的Cape Fear河河口，NC，通过松散耦合的物理建模方法，以得出结论的空间和时间模式的风暴潮和降雨，能够引起显着的复合影响的登陆。结果表明，强烈的外部雨带落在内陆部分的研究区域可以是一个驱动程序的河流激增复合（增加河流水位高达0.36米），而强烈的眼壁降雨沿着海岸可能会导致局部复合影响沿海河流和支流，如果峰值降雨发生在风暴潮峰值附近的时间。这些局部的复合影响可以导致确定的相互作用区，其中无论是单独的风暴潮还是单独的径流都不能完全解释观测到的最高水位。这些结果提供了关于降雨和风暴潮的相对时间和空间模式的见解，这些降雨和风暴潮能够在TC事件期间诱发复合洪水。暴雨潮和风暴潮峰值是复合洪泛的关键因子。热带气旋的外围雨带和内核降雨都是复合洪泛的驱动因子
Tropical cyclone (TC) events are major drivers of compound flooding due to the interaction of wind-driven storm surge and TC rainfall. Traditionally, coastal flood risk models have only taken into account surge flooding, even though it is known that the role of rainfall-runoff is critical. There is limited understanding about the types of TC events that are capable of producing significant compounding and how site conditions at the coast affect the extent to which storm surge and rainfall-runoff interact. This study investigates a suite of historical TCs making landfall near the Cape Fear River Estuary, NC, through a loosely coupled physical modeling methodology in order to draw conclusions about the spatial and temporal patterns of storm surge and rainfall that are able to induce significant compound impacts. Results indicate that intense outer rain bands falling over inland portions of the study area can be a driver of river-surge compounding (increasing river levels by up to 0.36 m), while intense eyewall rainfall along the coast can result in localized compound impacts to coastal streams and tributaries if peak rainfall occurs near the time of peak storm tide. These localized compound impacts can result in defined interaction zones, where neither storm tide alone nor rainfall-runoff alone can fully explain the observed maximum water levels. These results provide insight about the relative timing and spatial patterns of rainfall and storm surge that are capable of inducing compound flooding during TC events.Key PointsCompound flood impacts from historical TCs on North Carolina coast quantified through loosely coupled physical modeling method Spatial overlap and relative timing between rainfall, peak river flows, and peak storm tide are critical factors in observed compounding Both outer rain bands and inner core rainfall from TCs can be drivers of compound flooding