U.S. Geological Survey simulations of hydrodynamics and morphodynamics at Matanzas, FL during Hurricane Matthew (2016) and at Fire Island, NY during Hurricane Sandy (2012)

The Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST Warner and others, 2019; Warner and others, 2010) model was used to simulate ocean circulation, waves, and sediment transport to study barrier island breaches that occurred during Hurricane Matthew (2016) near Matazas FL, and Hurricane Sandy (2012) at Fire Island, NY. Hurricane Sandy was a Saffir-Simpson Category 2 hurricane that transited the Western Atlantic Ocean relatively far offshore of the US East Coast for five days until turning west to make landfall in New Jersey on 29 October 2012, causing extreme coastal erosion and flooding with destruction to residences and infrastructure along the East coast, particularly in the New York Bight. Maximum winds were ~50 m/s, minimum sea level pressure recorded was 940 mbar, maximum observed wave heights were ~10 m and storm surge was 3.5 m in NY City. During Sandy, barrier island breaching occurred at the site of a historical breach on an uninhabited section of Fire Island, NY. Research efforts have characterized the erosion, breaching, and recovery of Fire Island and post-storm LiDAR surveys provided topographic data for model initialization and comparison. Hurricane Matthew was a Saffir-Simpson Category 5 hurricane that impacted the Caribbean Islands and US East Coast in early October 2016. The hurricane paralleled the U.S. South Atlantic coastline within 50 km for two days until landfall in South Carolina on 8 October 2016. Extensive flooding and coastal erosion due to extreme storm surge, waves, and rainfall were experienced. Maximum wind speeds were ~75 m/s, maximum observed wave heights were ~8 m , and maximum storm surge was reported to be ~3 m in parts of Florida. Breaching of a small barrier separating the ocean from the Intracoastal Waterway south of Matanzas, FL occurred on 7 October 2016. The barrier is 1.7 km long and less than 0.15 km wide, characterized by a sandy beach with houses and a paved road running along parts of the dune crest. The breach location is 2 km south of Matanzas Inlet. Pre-storm and post-storm topo-bathymetric LiDAR were available to capture hurricane-driven morphological changes. The model employed a recently implemented infragravity wave model to represent the important effects of infragravity wave motions on nearshore water levels and sediment transport. The model simulated breaching. The breach simulated at Fire Island was 250 m west of the observed breach, whereas the breach simulated at Matanzas was within 100 m of the observed breach. Implementation of the vegetation module of COAWST to allow three-dimensional drag over dune vegetation at Fire Island improved model skill by decreasing flows across the back-barrier. Analysis of breach processes at Matanzas indicated that both far-field and local hydrodynamics influenced breach creation and evolution, including remotely generated waves and surge, but also surge propagation through back-barrier waterways. This work underscores the importance of resolving the complexity of nearshore and back-barrier systems when predicting barrier island change during extreme events. Further details are provided in Hegermiller et al., 2022. This is a summary page for the collection of 4 sub pages. -The first sub page is for the simualtion of Hurricane Matthew at Matanzas, FL. -The second sub page is for the simulation of Hurricane Sandy at Fire Island, NY using a constant bottom roughness over the barrier island. -The third sub page is for the simulation of Hurricane Sandy at Fire Island, NY using a variable bottom roughness over the barrier island. -The fourth sub page is for the simulation of Hurricane Sandy at Fire Island, NY using a variable bottom roughness and vegetation drag over the barrier island. Reference cited: Hegermiller, C.A., Warner, J.C., Olabarrieta, M., Sherwood, C.R., and Kalra, T.S., 2002, Barrier island breach dynamics during Hurricanes Sandy and Matthew: Journal of Geophysical Research - Earth Surface, https://doi.org/10.1029/2021JF006307. Warner, J.C., Armstrong, Brandy, He, Ruoying, and Zambon, J.B., 2010, Development of a coupled ocean-atmosphere-wave-sediment transport (COAWST) modeling system: Ocean Modelling, v. 35, issue 3, p. 230-244. Warner, J.C., Ganju, N.K., Sherwood, C.R., Tarandeep, K., Aretxabaleta, A., He, R., Zambon, J., and Kumar, N., 2019, Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System: U.S. Geological Survey Software Release, 23 April 2019, https://doi.org/10.5066/P9NQUAOW. (URL for the specific version of the code used for these model results: https://code.usgs.gov/coawstmodel/COAWST/-/tags/COAWST_v3.7)

本研究采用耦合海洋-大气-波浪-泥沙输运（Coupled Ocean-Atmosphere-Wave-Sediment Transport, COAWST，Warner等，2019；Warner等，2010）模型，对海洋环流、波浪与泥沙输运过程开展数值模拟，旨在探究两场极端飓风期间的障壁岛溃决事件：分别为2016年飓风马修（Hurricane Matthew）影响美国佛罗里达州马坦萨斯近岸区域，以及2012年飓风桑迪（Hurricane Sandy）影响纽约州火岛（Fire Island）区域。

飓风桑迪为萨菲尔-辛普森（Saffir-Simpson）二级飓风，其在西大西洋远离美国东海岸的远海区域移动长达5天，最终于2012年10月29日向西转向并在新泽西州登陆，引发极端海岸侵蚀与洪涝灾害，对美国东海岸沿线尤其是纽约湾（New York Bight）的住宅与基础设施造成严重破坏。该飓风最大风速约50 m/s，实测最低海平面气压为940 mbar，纽约市观测到的最大波高约10 m，风暴增水达3.5 m。在飓风桑迪影响期间，纽约州火岛一处无人区段的历史溃口位置发生了障壁岛溃决。

此前研究已对火岛的侵蚀、溃决与恢复过程开展特征分析，风暴后激光雷达（Light Detection and Ranging, LiDAR）测量获取的地形数据，被用于模型初始化与结果验证。

飓风马修为萨菲尔-辛普森五级飓风，于2016年10月初影响加勒比群岛与美国东海岸。该飓风沿美国南大西洋海岸线在50 km范围内平行移动达2天，最终于2016年10月8日在南卡罗来纳州登陆。此次飓风引发极端风暴增水、波浪与降雨，造成大范围洪涝与海岸侵蚀。其最大风速约75 m/s，实测最大波高约8 m，佛罗里达州部分区域的风暴增水峰值据报达约3 m。2016年10月7日，佛罗里达州马坦萨斯南部一处分隔海洋与障壁后水道（Intracoastal Waterway）的小型障壁滩发生溃决。该障壁滩长1.7 km，宽度不足0.15 km，主体为沙质海滩，沿线沙丘脊段分布有住宅与铺装道路。溃口位置位于马坦萨斯水道以南2 km处。风暴前后的地形-水深激光雷达数据，可用于捕捉飓风驱动的地貌变化过程。

本模型采用新近集成的亚重力波（infragravity wave）模块，以表征亚重力波运动对近岸水位与泥沙输运的重要影响。模型成功模拟了障壁岛溃决过程：在火岛模拟得到的溃口位置较实测位置西偏250 m，而在马坦萨斯模拟得到的溃口位置与实测位置偏差在100 m以内。在火岛模拟中，引入COAWST的植被模块以实现沙丘植被的三维拖曳效应，通过降低越障水流强度，提升了模型模拟精度。对马坦萨斯溃决过程的分析表明，远场与局地水动力过程共同影响了溃口的形成与演化，其中既包括远程传播的波浪与风暴增水，也包括风暴增水通过障壁后水道的传播过程。本研究凸显了在极端事件期间预测障壁岛地貌变化时，解析近岸与障壁后系统复杂性的重要性。更多细节可参见Hegermiller等，2022的研究成果。

本页面为该数据集汇总页，共包含4个子页面：
1. 第一个子页面：佛罗里达州马坦萨斯区域飓风马修的数值模拟
2. 第二个子页面：采用固定底糙率方案的纽约州火岛区域飓风桑迪数值模拟
3. 第三个子页面：采用可变底糙率方案的纽约州火岛区域飓风桑迪数值模拟
4. 第四个子页面：采用可变底糙率与沙丘植被拖曳方案的纽约州火岛区域飓风桑迪数值模拟

引用文献：
1. Hegermiller, C.A., Warner, J.C., Olabarrieta, M., Sherwood, C.R., and Kalra, T.S., 2022, Barrier island breach dynamics during Hurricanes Sandy and Matthew: *Journal of Geophysical Research - Earth Surface*, https://doi.org/10.1029/2021JF006307.
2. Warner, J.C., Armstrong, Brandy, He, Ruoying, and Zambon, J.B., 2010, Development of a coupled ocean-atmosphere-wave-sediment transport (COAWST) modeling system: *Ocean Modelling*, v. 35, issue 3, p. 230-244.
3. Warner, J.C., Ganju, N.K., Sherwood, C.R., Tarandeep, K., Aretxabaleta, A., He, R., Zambon, J., and Kumar, N., 2019, Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System: U.S. Geological Survey Software Release, 23 April 2019, https://doi.org/10.5066/P9NQUAOW. （本次模型结果所用代码版本的链接：https://code.usgs.gov/coawstmodel/COAWST/-/tags/COAWST_v3.7）