RAPID: Hurricane Harvey Rapid Response: In-Situ Barrier Island Storm Impact and Recovery Measurements of Hydrodynamics, Morphodynamics, and Sedimentation Acr. Hog and F. Island TX

由于部署的提前通知时间短、仪器故障或丢失的可能性以及特定地点的实际风暴影响的不确定性，很难获得对沿海系统的极端风暴影响的快速响应现场测量。该项目提高了测量受极端事件影响的障碍岛系统表面的详细水动力过程(海流和海浪)的能力。这些数据将提供前所未有的信息，以增强风暴影响的地面真实预测建模能力。对选定的两个实地地点(猪岛和福莱茨群岛)的即时和中期(数周至数月)恢复情况的详细分析将进一步阐明障碍岛系统的风暴后恢复动态，这对于在相对海平面上升和可能出现更频繁和/或更强烈的热带风暴的情况下理解这一动态至关重要。反过来，这些知识可以帮助增强沿海社区的复原力。研究小组在2017年8月25日飓风哈维作为4级风暴登陆的三天前，在得克萨斯州海湾中部和上游海岸线部署了一套五个“快速反应部队”(RRU)。RRU站点提供了在登陆点和加尔维斯顿之间大约一半的两个地点的详细测量，并能够对风暴对这两个系统的影响进行详细的比较研究。RRU包含用于记录水位波动和波高的压力传感器、用于测量海流和轨道波速度的倾斜海流计、声学多普勒测速仪和GoPro延时成像系统。这些数据将在使用无人驾驶航空系统(UAS)和标准摄影测量处理算法生成的风暴前后数字高程模型(DEM)的背景下进行解释。风暴后的快速反应活动还包括水下和涉水深度实时动态(RTK)海滩剖面，以及表层沉积物采样和洗涤沉积物取心。最初的UAS每周航班计划，随后是每月调查，将记录飓风过后屏障系统的恢复情况。

Rapid response field measurements of extreme storm impacts to coastal systems are difficult to obtain due to short advance notice times for deployment, potential for instrument failure or loss, and uncertainty in actual storm impact for specific locations. This project advances capabilities to measure detailed hydrodynamic processes (currents and waves) across the surface of barrier island systems impacted by extreme events. The data will provide unprecedented information to enhance and ground-truth predictive modeling capabilities of storm impacts. Detailed analysis of immediate and medium term (weeks to months) recovery of the two selected field sites (Hog and Folletts Islands) will shed further light on post-storm recovery dynamics of barrier island systems that are critical to understand in the context of relative sea level rise and the potential for more frequent and/or intense tropical storms. In turn, this knowledge can help bolster the resiliency of coastal communities.The research team was able to deploy a set of five "Rapid Response Units" (RRUs) along the central and upper Texas Gulf coastline three days prior to Hurricane Harvey's landfall as a Category 4 storm on August 25, 2017. The RRU sites provide detailed measurements at two locations roughly half way between the landfall point and Galveston, and enable detailed comparative studies of the storm's impacts on these two systems. The RRUs contain pressure transducers to record water level fluctuations and wave heights, tilt current meters to measure current and orbital wave velocities, acoustic Doppler velocimeters, and GoPro time-lapse imaging systems. These data will be interpreted in the context of pre- and post-storm digital elevation models (DEMs) generated using an unmanned aerial system (UAS) and standard photogrammetric processing algorithms. Post-storm rapid response activities also include subaerial and wading-depth real time kinematic (RTK) beach profile transects and surface sediment sampling and coring of washover deposits. An initial program of weekly UAS flights, followed later by monthly surveys, would document recovery of the barrier system following the hurricane.