Collaborative Research: Morphodynamic simulations of coastal storms and overwash to characterize back-barrier lake stratigraphies

飓风对美国东部的沿海社区构成了重大危害，产生了强风和海浪、海岸洪水和侵蚀。这些风暴通常会导致洪水泛滥，这是一个水和沉积物流过海岸屏障，侵蚀海滩，并在屏障上方和后面沉积沉积物的过程。在飓风的书面记录和卫星记录之前，地球科学家经常使用沿海池塘中的溢流沉积物来推断过去飓风发生的时间。这些过去飓风活动的沉积记录有助于限制飓风在一段海岸线上登陆的可能性，或有助于了解飓风频率随过去气候变化的变化，通常被纳入危险评估。然而，这些沉积记录仅限于重建过去风暴的频率，而对这些事件的规模或轨迹的推断仍然是初步的。在这个项目中，研究人员将利用海岸泥沙输送的计算机模拟的最新进展，开发一种从溢流沉积物中重建风暴强度和轨迹的新方法。该项目将把现场观测的沉积物岩心溢流与对观测和模拟的飓风的最新模拟相结合，以：(I)评估风暴性质对屏障后环境中溢流沉积的影响，(Ii)诊断沉积模式对地貌变化的敏感性，以及(Iii)将风暴强度和轨迹与溢流沉积的性质联系起来。这项工作将定量重建新英格兰南部的飓风强度--这是一个人口稠密的地区，容易受到热带气旋的影响--将该地区飓风活动的历史记录追溯到几个世纪前，以深入了解在该地区登陆的史前飓风的强度和轨迹。研究人员预计，这里开发的综合和可扩展的方法将适用于美国和海外其他易受热带和温带气旋影响的海岸线，并将促进预测和缓解海岸侵蚀和洪水的关键挑战。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Hurricanes constitute major hazards to coastal communities of the eastern United States, generating strong winds and waves, coastal flooding, and erosion. These storms often induce overwash, a process where water and sediments flow over coastal barriers, erode the beach, and deposit sediments atop and behind the barrier. Geoscientists often use deposits of overwash in coastal ponds to infer when hurricanes occurred in the past, prior to written and satellite records of hurricanes. These sedimentary records of past hurricane activity are useful for constraining the probability of a hurricane making landfall on a stretch of coastline, or for understanding changes in hurricane frequency in response to past changes in climate, and are commonly integrated into hazard assessments. However, these sedimentary records are limited to reconstructing the frequency of past storms, while inferences into the magnitude or track of these events remain preliminary. In this project, the investigators will harness recent advances in computer simulations of coastal sediment transport to develop a new approach for reconstructing storm strength and track from overwash deposits. This project will integrate field-based observations of overwash from sediment cores with state-of-the-art simulations of observed and simulated hurricanes to: (i) evaluate the influences of storm properties on overwash deposition in back-barrier settings, (ii) diagnose the sensitivity of depositional patterns to geomorphic change, and (iii) relate storm strength and track to the properties of overwash deposits. This work will deliver quantitative reconstructions of hurricane magnitude for southern New England — a heavily-populated region that is vulnerable to tropical cyclones — extending the historical record of hurricane activity in this region back centuries to provide insight into strengths and tracks of prehistoric hurricanes that made landfall in this region. The investigators anticipate that the integrative and scalable approach developed here will be applicable to other coastlines in the United States and abroad that are vulnerable to tropical and extratropical cyclones, and will facilitate the critical challenge of predicting and mitigating against coastal erosion and flooding.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.