RAPID: Morphological Effects of Extreme Sea-Level Anomalies

RAPID：极端海平面异常的形态效应

• 批准号: 1531512
• 负责人: Peter Ruggiero
• 金额: $ 4.5万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-15 至 2017-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1531512&HistoricalAwards=false
• 关键词: RAPID; Morphological; Effects; Extreme; Sea

A non-technical description of the project, which explains the project's significance and importanceCoastal erosion is a problem of national and global importance. As more people live along the shore, it is becoming increasingly vital to forecast how storms and other weather systems can alter the landscapes of coastlines. This RAPID project will collect intensive field data from the Oregon coastline during a period of elevated sea level and El Niño conditions that will make numerical models of beach movement and erosion more accurate. Numerical models of coastal processes are widely used by federal/state government agencies, local planners, and consultancies for a range of engineering and planning applications; accordingly, enhancing the quantitative accuracy of morphological evolution in these models has the potential to improve the quality of many products and services. A technical description of the projectThis RAPID project will implement a beach and dune topographic surveying campaign in the Netarts littoral cell, Oregon to quantify the impacts of extreme sea level anomalies on beach morphology. Hypotheses to be tested are whether 1) the majority of the dune-backed coastline within Oregon's headland-bound littoral cells will experience the "collision regime" of the Sallenger storm impact scale approximately 10-15% more during El Niño than during normal years. Dunes along the coast will also experience the "overwash regime" significantly more than during a typical year; 2) the southern extent of littoral cells will experience significant erosion and will be more impacted than the north. Gradients in longshore sediment transport will erode on the order of tens of thousands of cubic meters of sand from the southern ends of littoral cells with that sediment being transported both offshore and northward; and 3) Cross shore sediment supply to the beach following storms and at the end of the anomalous period, initiating the recovery phase for the dunes, will be highly spatially variable based on beach morphometrics, but will be strongly correlated to local gradients in longshore sediment transport. Although there is a general sense of how sea level anomalies and El Niño events impact beaches and dunes along the U.S. West Coast, there are few data sets available and the rates and mechanisms of onshore feeding of sediment are poorly documented. This research will quantify the sediment volume lost from the beach during each storm event and subsequently track the spatial and temporal trends in beach recovery throughout the winter and spring.

该项目的非技术描述，解释了该项目的重要性和重要性沿海侵蚀是国家和全球重要性的问题。随着越来越多的人居住在岸上，预测风暴和其他天气系统如何改变海岸线的景观变得越来越重要。这个快速的项目将在升高的海平面和厄尔尼诺现象的时期从俄勒冈海岸线收集密集的现场数据，这将使海滩运动和侵蚀的数值模型更加准确。沿海流程的数值模型被联邦/州政府机构，当地规划师和一系列工程和规划应用的顾问广泛使用；因此，在这些模型中提高形态演化的定量准确性有可能提高许多产品和服务的质量。该项目快速项目的技术描述将在俄勒冈州Netarts Littoral细胞中实施海滩和沙丘地形测量活动，以量化极端海平面异常对海滩形态的影响。要测试的假设是1）俄勒冈州岬角结合的沿海细胞内的大多数沙丘支持的海岸线是否会在正常年份遭受Sallenger风暴影响量表的“碰撞状态”大约增加10-15％。海岸的沙丘也将比典型的一年要多得多。 2）沿海细胞的南部范围将遭受重大侵蚀，并且比北部更受影响。漫长岸沉积物中的梯度将在沿海细胞南端的数万立方米沙子的秩序中侵蚀，而这种沉积物都被运输到海上和北方。 3）在暴风雨后和异常时期结束时，越过海滩的跨岸沉积物供应，启动了沙丘的恢复阶段，尽管人们普遍认为海平面异常和厄尔尼诺现象如何影响美国西海岸的海滩和沙丘，但很少有数据集可用的数据集，而且在供应量不佳的情况下，供应不佳。这项研究将量化每次风暴事件中从海滩损失的沉积物量，然后在整个冬季和春季跟踪海滩恢复的空间和临时趋势。