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造成的破坏性影响凸显了提高沿海社区快速应对自然灾害并从自然灾害中恢复的能力的必要性。 目前有一种趋势是实施“软”工程解决方案，例如用土工布沙容器（GSC）加固沙丘以提高弹性，而不是传统的硬化结构（如石护岸）。 这些有可能保护社区免受较小风暴事件（例如 25 年风暴）的影响，同时考虑到海平面上升率和风暴频率的不确定性，提供设计灵活性。 与硬化结构相比，“软”工程解决方案对屏障海滩系统自然形态的破坏也较小。 然而，波浪攻击下加固沙丘稳定性的影响机制仍存在相当大的不确定性。 该快速响应研究 (RAPID) 项目的目标是收集易腐烂的数据，以评估纽约州蒙托克 1000 米长的沙丘部分的稳定性和性能，该部分采用 GSC 加固，该沙丘在 2016 年 9 月受到热带风暴 Hermine 的影响。沙丘于 2016 年 3 月建成，热带风暴 Hermine 导致保护护堤完全侵蚀，GSC 核心暴露，底层沙丘发生移动。 GSC。 将构建侵蚀海滩（地形）和近岸测深的详细 3D 数字高程模型。 这将通过两项调查来完成：使用无人机系统（UAS）的空中激光雷达调查以及船载激光雷达和干涉声纳系统的组合。 这些数据将提供波浪作用对 GSC 加固沙丘影响的详细案例研究。 这将允许将数值和波槽研究的结果应用到实验室无法重现的实际现场案例中。 据推测，当前的稳定性方程是不保守的，因为它们低估了与缩小规模实验相关的土工织物容器的水力稳定性。 对本案例研究的分析还将提高我们对加固沙丘是否充当“软”海岸结构并且不会显着改变海岸线自然形态的理解。