RAPID: Assessment of coastal & offshore change due to Hurricane Florence: Wrightsville Beach, North Carolina

众所周知，在低洼沿海地区登陆的飓风，如美国东南海岸外岸的屏障岛，会对海岸线和安装的基础设施造成重大影响，这些设施比正常的海浪和潮涌更高、更强。风暴的影响范围从轻微的海滩和沙丘侵蚀到完全的沿海破坏（例如，2016年的飓风马修和2018年在佛罗里达州墨西哥海滩登陆的飓风迈克尔）。大量的科学研究已经记录了这些风暴对海滩和其他海底暴露部分海岸线的严重影响。然而，人们对近海地区（从海滩向海延伸）在沿海反应和恢复力方面所起的作用知之甚少。这项研究利用船上的海洋地球物理调查和其他技术来绘制赖特斯维尔海滩近海水域的海底地图，帮助填补了这一空白，赖特斯维尔海滩位于北卡罗来纳州威尔明顿以东，靠近飓风佛罗伦萨登陆的地方。赖特斯维尔海滩与休闲区、商业和住宅建筑有关。这项工作的目标是记录佛罗伦萨飓风造成的海底测深、地貌和沉积物分布的变化，直至水深约10米。所得到的数据将被用来试图确定为什么对海滩的影响，即使是在同一海滩上相隔很近的地方，也会有很大的不同。这项工作的更广泛影响包括培训学生，向海岸管理人员、当地政策制定者和公众提供有关飓风等强风暴与海滩和近海地区之间联系的信息。该项目旨在了解北卡罗来纳州Wrightsville海滩的近海区域在三个地点观察到的高度变化的海滩侵蚀中所起的作用，该区域靠近飓风佛罗伦萨登陆中心。一系列船载海洋测量技术，包括单波束测深、侧扫声纳和海底抓取采样技术的组合，将用于描述这三个位置的特征。这些新数据将与佛罗伦萨之前的海滩高程数据和离岸调查数据进行比较，并将通过当地近海浮标公开获取的佛罗伦萨飓风引起的风和波数据进行增强。这些数据将用于测试、验证，并与荷兰代尔夫特沿海小组开发的SWAN数值水动力模型的预测结果进行比较。如果能在数据/观测结果与模式输出之间找到良好的相关性，其他地方的沿海科学家和管理人员就可以采用类似的方法，更好地评估其他堰洲岛地点飓风袭击的潜在风险地区和减灾战略。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Hurricanes that make landfall at low-lying coastal regions, such as barrier-islands like those on the Outer Banks of the US southeast coast, are known to cause significant impacts on the coastline and installed infrastructure within reach of higher and more forceful than normal waves and the tidal surge. Storm impacts can range from minor beach and dune erosion to complete coastal devastation (as seen, for example, with Hurricane Matthew in 2016 and with Hurricane Michael in 2018 that came ashore at Mexico Beach, FL). Abundant scientific research has documented the serious impacts these storms have on beaches and other subaerially exposed parts of the coastline. However, much less is known about the role the offshore region, extending seaward from beaches, plays in coastal response and resilience. This research helps fill this gap by using shipboard marine geophysical surveys and other techniques to map the seabed in coastal waters offshore Wrightsville Beach that lies just east of Wilmington, North Carolina and is near where Hurricane Florence made landfall. Wrightsville Beach is associated with recreational areas and commercial and residential buildings. Goals of the work are to document changes in seabed bathymetry, geomorphology, and sediment distribution resulting from Hurricane Florence out to water depths of ~10 meters. The resulting data will be used to try and determine why effects on beaches, even at locations on the same beach that are closely spaced, can be very different. Broader impacts of the work include student training and providing information to coastal managers, local policy makers, and the public about the link between strong storms, like hurricanes, and beaches and the offshore region. This project seeks to understand what role the offshore region at Wrightsville Beach, North Carolina, which was close to the center of Hurricane Florence's landfall, played in the highly variable beach erosion observed at three locations. A range of shipboard marine survey techniques that include a combination of single-beam bathymetry, side scan sonar, and seabed grab sampling techniques, will be used to characterize the three locations. These new data will be compared to pre-Florence beach elevation data and off shore surveys and will be augmented by Hurricane Florence-induced wind and wave data that are publicly accessible from local offshore buoys. These data will be used to test, validate, and compare with predictions obtained from the SWAN numerical hydrodynamic model developed by the Delft coastal group in The Netherlands. If good correlations can be found between the data/observations and model output, similar methods could be adopted and employed by coastal scientists and managers elsewhere to better assess potential risk areas and mitigation strategies for hurricane strikes at other barrier island locations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.