Modelling Wave-Driven Setup

波驱动设置建模

• 批准号: 0622844
• 负责人: Britt Raubenheimer
• 金额: $ 22.02万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0622844&HistoricalAwards=false
• 关键词: Modelling; Wave; Driven; Setup

ABSTRACTOCE-0622844In this study, scientists at Woods Hole Oceanographic Institution will develop and validate models for the fluid and sediment processes that affect the evolution of the shoreline over periods of days to months. Gradients in wave momentum fluxes (radiation stresses) drive the near-shore circulation which in turn drives sediment transport. One important facet of the near-shore circulation is wave-driven setup, which is an elevation of mean water levels near the shoreline. Observations of setup were made in 1997 near Duck, North Carolina and in 2000 and 20003 near La Jolla, CA. These studies have shown that prior estimates of the cross-shore radition stress, which were based on a linear theory of onshore wave energy from sea swell, are smaller than what is observed. This study will extend a numerical model to include four previously neglected processes: wave rollers, bottom stress, wave nonlinearities, and infragravity wave reflection. The predictions of that model will then be compared with existing field and laboratory observations.Laboratory observations of the vertical profile of flows will be used to compare linear and nonlinear expressions for wave energy and radiation stress. If nonlinearities are shown to be important, depth-averaged nonlinear expressions will be examined and incorporated in the setup models. Additionally, the importance of alongshore bathymetric inhomogenities to the wave-driven setup will be examined using simulations of the quasi three-dimensional NearShore Community and Delft3D models.During storms, wave-driven setup has been observed to increase the seal level more than a meter. As became clear during Hurricane Katrina, flood damage by a combination of storm surge and wave setup can result in a significant cost to society. The model that is being developed in this study could be useful to coastal managers who are tasked with the prediction of coastal flooding. This study forms the basis of a PhD dissertation and results will provide material for internet-based undergraduate classes in New England.

在这项研究中，伍兹霍尔海洋研究所的科学家们将开发和验证影响海岸线演变的流体和沉积物过程的模型，这些过程持续数天至数月。波浪动量通量中的动量（辐射应力）驱动近岸环流，近岸环流又驱动沉积物输运。近岸环流的一个重要方面是波浪驱动的设置，这是海岸线附近平均水位的升高。1997年在北卡罗来纳州的达克附近以及2000年和20003年在加利福尼亚州的拉霍亚附近进行了观测。 这些研究表明，先前估计的跨海岸辐射应力，这是基于一个线性理论的陆上波能从海涌，是小于所观察到的。这项研究将扩展一个数值模型，包括四个以前被忽视的过程：波辊，底部应力，波的非线性，和亚重力波反射。然后将该模型的预测结果与现有的实地和实验室观测结果进行比较，将利用实验室对水流垂直剖面的观测结果来比较波能和辐射应力的线性和非线性表达式。如果非线性被证明是重要的，深度平均的非线性表达式将被检查，并纳入设置模型。此外，沿岸水深不均匀性的重要性，以波驱动的设置将使用准三维近岸社区和Delft3D models.During风暴模拟检查，波驱动的设置已被观察到增加密封水平超过一米。正如在卡特里娜飓风期间变得明显的那样，风暴潮和波浪组合造成的洪水破坏可能会给社会带来重大损失。本研究中开发的模型可能对负责预测沿海洪水的沿海管理人员有用。本研究构成了博士论文的基础，其结果将为新英格兰的基于互联网的本科课程提供材料。