Abstract Coastal hazard at the residential scale, resulting from the combined effects of storm surge and waves including dynamic set-up and wave runup, is assessed for the local 100-year Synthetic Design Storm (SDS) in Narragansett, RI, USA, based on high resolution (2 m) simulations with the nonlinear phase-resolving Boussinesq wave model FUNWAVE. The accuracy of wave-flow-structure interaction modeling is improved using a built-up DEM, defined by adding coastal structures to the bare-earth DEM. In addition, bathymetry and topography are modified to reflect post-storm conditions based on simulating the same storm with the morphodynamic model XBeach. Comparisons of FUNWAVE results with those of the phase-averaged model STWAVE, for the same storm conditions, show that including individual wave effects increases the inundated area by 13% and maximum water levels (TWL) across the shoreline by 11%, in average; however, in high runup areas (such as along exposed structures), the predicted maximum water levels can increase by up to 100%. FUNWAVE predicts maximum runups on the order of ∼ 1 . 5 H s (with H s the offshore significant wave height), which is consistent with empirical formulae for steep seawalls (Van der Meer, 2002), and these occur at the most exposed structures, which historical records show have been periodically damaged by large storms. The maximum momentum forces predicted by FUNWAVE are much larger than those derived from STWAVE simulations (based on linear wave theory and assuming Rayleigh distributed waves), and also occur on the most exposed structures. The study provides a quantitative assessment of the local coastal hazard associated with the selected SDS at the scale of individual structures, and stresses the importance of accurately modeling individual wave effects, runups and associated forces in coastal hazard assessment modeling studies.

中文翻译：

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使用相位解析波模型评估极端风暴造成的沿海危害：美国罗德岛纳拉甘塞特的案例研究

摘要 针对美国罗德岛纳拉甘西特当地 100 年合成设计风暴 (SDS)，评估了由风暴潮和波浪的综合影响（包括动力设置和波浪爬高）引起的住宅规模的沿海灾害，基于使用非线性相位分辨 Boussinesq 波模型 FUNWAVE 进行高分辨率 (2 m) 模拟。波浪-流-结构相互作用建模的准确性使用组合 DEM 提高，该 DEM 通过将海岸结构添加到裸地 DEM 来定义。此外，基于使用形态动力学模型 XBeach 模拟同一风暴，修改了测深和地形以反映风暴后的条件。对于相同的风暴条件，FUNWAVE 结果与相位平均模型 STWAVE 的结果的比较，表明包括单个波浪效应会使整个海岸线的淹没区域平均增加 13%，最大水位 (TWL) 增加 11%；然而，在高水位区域（例如沿裸露结构），预测的最高水位可能会增加 100%。FUNWAVE 预测最大运行量约为 1 。5 H s（其中 H s 为海上有效波高），这与陡峭海堤的经验公式一致（Van der Meer，2002），并且这些发生在最暴露的结构中，历史记录显示这些结构已被周期性破坏风暴。FUNWAVE 预测的最大动量力远大于 STWAVE 模拟（基于线性波理论并假设瑞利分布波）得出的那些，并且也发生在最暴露的结构上。