Runups of Unusual Size: Predicting Unexpectedly Large Swash Events

这个项目的目标是提高我们对海洋海滩上异常大浪上升事件的理解。这样的上升事件只出现在很小一部分海浪中，但它们对预测风暴期间的沙丘侵蚀、淹没和沿海洪水很重要。第二种不寻常的上升事件的特点还在于，即使上升的向陆地延伸的范围在统计上不是极端的，它也是突然和意外的。这些大型和不寻常的上升事件是美国太平洋西北部溺水死亡的主要原因。为了了解意外大型运行事件的原因，并开始预测它们的潜在发生，该项目将使用现有数据，新的多年数据集和数值模型模拟的层次结构，并将事件与各种生成机制联系起来。最后，将开发和测试一个模型来预测此类事件的风险。该团队将与国家气象局办公室合作，并探索向公众传播恶劣天气预报的其他渠道。除了提高公共安全外，该项目还将有助于海岸管理工作。这些努力依靠预测勾勒出适于发展的洪水危险区和地区。此外，该研究的数值模拟部分的发现将记录并可能提高近岸水动力模型的准确性/能力，这将有利于其他地理环境下的沿海地区管理。最后，该项目将通过直接让研究生和本科生参与研究来促进教育工作，特别注意来自代表性不足群体的个人的参与。在过去的十年中，对冲刷带流体动力学的研究取得了持续的进展，其中大部分集中在体积和极端累积统计的特征上。然而，大事件，特别是意外事件的物理原因却很少受到重视。该项目将进行数据收集和分析以及数值模型研究，旨在区分与叠加相关的线性生成机制和与井眼捕获相关的非线性生成机制，入射波-次重力波相互作用以及大型和意外启动事件的上冲-反冲事件。两个截然不同的海滩，俄勒冈州的玛瑙海滩和北卡罗来纳州的达克海滩之间的形态动力学差异，将有助于揭示海滩类型在大型和不寻常的上升事件产生中的作用。这些观测将使研究小组能够测试和改进风暴期间简单的极端运行参数模型的技巧。

The goal of this project is to improve our understanding of unusually large wave runup events on ocean beaches. Such runup events are seen with only a small fraction of the waves, yet they are important for the prediction of dune erosion, inundation and coastal flooding during storms. A second type of unusual runup event is also distinguished in that it is sudden and unexpected even if the landward reach of the runup is not a statistical extreme. These large and unusual runup events are the leading cause of death by drowning along the U.S. Pacific Northwest. In order to understand the causes of unexpectedly large runup events, and to begin to forecast their potential occurrence, this project will use existing data, a new multi-year data set and a hierarchy of numerical model simulations and link the events to various generation mechanisms. Finally a model will be developed and tested for forecasting the risk of such events. The team will work with the National Weather Service offices as well as exploring other outlets to communicate severe event forecasts to the public. In addition to increased public safety, this project will also help coastal management efforts. These efforts rely on predictions to outline flood hazard zones and regions appropriate for development. Additionally, findings from the numerical modeling portion of the study will document and potentially advance the accuracy/capabilities of nearshore hydrodynamic models, which will benefit coastal zone management in other geographic settings. Finally the project will contribute to education efforts by directly involving graduate and undergraduate students in the research, paying specific attention to the entrainment of individuals from under-represented groups.The study of swash zone hydrodynamics has seen sustained progress over the last decade, with much of the focus on the characterization of bulk and extreme runup statistics. However, the physical causes of large, and especially of unexpected, events have received considerably less attention. This project will conduct data collection and analysis and numerical model studies designed to distinguish between linear generation mechanisms related to super-position and nonlinear generation mechanisms related to bore-bore capture, incident wave-infragravity wave interactions and uprush-backwash events for large as well as unexpected runup events. Morphodynamic differences between two drastically different beaches, Agate Beach, OR and Duck, NC, will help reveal the role of beach type on the generation of both large and unusual runup events. The observations will allow the team to test and improve the skill of simple extreme runup parametric models during storms.