RAPID: Lidar and Sonar Surveys of a Dune Reinforced with Geotextile Sand Containers Impacted by Tropical Storm Hermine

RAPID：对受热带风暴 Hermine 影响的用土工布沙容器加固的沙丘进行激光雷达和声纳测量

• 批准号: 1719671
• 负责人: Christopher Baxter
• 金额: $ 6.2万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-15 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1719671&HistoricalAwards=false
• 关键词: RAPID; Lidar; Sonar; Surveys; Dune

The devastating effects of Hurricane Sandy in 2012 on the northeast United States highlighted the need to improve the ability of coastal communities to quickly respond and rebound from natural hazards. There is a trend towards implementing "soft" engineering solutions such as dunes reinforced with Geotextile Sand Containers (GSC) to improve resiliency rather than traditional hardened structures like stone revetments. These have the potential to protect communities from smaller storm events (e.g. 25-year storms) while at the same time providing flexibility in design considering the uncertainty regarding rates of sea level rise and storm frequency. "Soft" engineering solutions may also be less disruptive to the natural morphology of barrier beach systems than hardened structures. However, there is still considerable uncertainty regarding the mechanisms that affect the stability of reinforced dunes under wave attack. The objective of this Rapid Response Research (RAPID) project is to collect perishable data to assess the stability and performance of a 1000 m section of a dune reinforced with GSCs in Montauk, NY that was impacted by Tropical Storm Hermine in September 2016. The reinforced dune was constructed in March 2016, and Tropical Storm Hermine resulted in complete erosion of the protective berm, exposure of the GSC core, and movement of the lower level of GSCs. A detailed 3-D digital elevation model of both the eroded beach (topography) as well as the near-shore bathymetry will be constructed. This will be accomplished through two surveys: an aerial LIDAR survey using an Unmanned Aerial System (UAS) and a combined ship-mounted LIDAR and interferometric sonar system. These data will provide a detailed case study of the effects of wave action on a dune reinforced with GSCs. This will allow for the application of findings from numerical and wave flume studies to an actual field case at a scale not reproducible in the laboratory. It is hypothesized that current stability equations are unconservative in that they underpredict the hydraulic stability of geotextile containers associated with reduced scale experiments. Analysis of this case study will also improve our understanding of whether reinforced dunes perform as "soft" coastal structures and do not significantly modify the natural morphology of the shoreline.

2012年，桑迪飓风对美国东北部的毁灭性影响强调，有必要提高沿海社区快速反应和反弹自然危害的能力。 实施“软”工程解决方案的趋势，例如用土工织物砂容器（GSC）加强的沙丘来提高弹性，而不是传统的硬化结构，例如石材静电。 这些潜力有可能保护社区免受较小的风暴事件（例如25年的风暴），同时考虑到海平面上升和暴风雨频率的不确定性，在设计方面提供了灵活性。 “软”工程解决方案也可能比硬化的结构对屏障海滩系统的自然形态造成的破坏。 但是，关于影响波攻击下加固沙丘稳定性的机制仍然存在很大的不确定性。 The objective of this Rapid Response Research (RAPID) project is to collect perishable data to assess the stability and performance of a 1000 m section of a dune reinforced with GSCs in Montauk, NY that was impacted by Tropical Storm Hermine in September 2016. The reinforced dune was constructed in March 2016, and Tropical Storm Hermine resulted in complete erosion of the protective berm, exposure of the GSC core, and movement of the lower level of GSC。 将构建一个详细的3D数字高程模型，包括侵蚀的海滩（地形）以及近岸的测深。 这将通过两项调查来完成：使用无人驾驶系统（UAS）的空中调查以及船上安装的LiDAR和干涉声音系统。 这些数据将提供详细的案例研究，了解波动对GSC增强的沙丘的影响。 这将允许将发现从数值和波浪水槽研究中应用于实验室不可再现的实际田间情况。 假设当前的稳定性方程是非保守的，因为它们低估了与缩小实验相关的土工布容器的液压稳定性。 对该案例研究的分析还将提高我们对加固沙丘是否作为“软”沿海结构的理解，并且不会显着改变海岸线的自然形态。