Classification of beach response to extreme storms
Classification of beach response to extreme storms
复制标题
DOI：
10.1016/j.geomorph.2017.07.022
复制
发表时间：
2017-10
期刊：
影响因子：
3.9
通讯作者：
Olivier Burvingt;G. Masselink;P. Russell;T. Scott
中科院分区：
文献类型：
--
作者：
Olivier Burvingt;G. Masselink;P. Russell;T. Scott
极端风暴是导致全球海岸线迅速变化的原因。在2013/14冬季，欧洲西海岸经历了一系列大型风暴引发的波浪事件，这是过去60年来波浪最活跃的时期。英格兰西南海岸在此期间经历了显著的地貌变化，但尽管受到相同的风暴序列，但表现出一系列空间可变和复杂的形态反应。在这里，我们使用2013/14风暴响应沿着英格兰西南海岸作为一个自然的现场实验室，并解释这种变化的风暴响应通过引入和评估的一个新的分类如何桑迪和砾石海滩响应极端风暴。基于净体积变化（dQnet）和一个新参数（沿岸变化指数（LVI）），使用来自157个海滩地点的风暴前和风暴后机载光探测和测距（LiDAR）数据的独特数据集进行了聚类分析，该参数量化了沿岸形态变化在海滩响应中的变化。海滩的响应主要有四种类型：（1）完全裸露的海滩，经历了大的和沿岸均匀的沉积物流失（dQnet ≤ 100 m3·m− 1）;（2）经历了中度沿岸均匀沉积物损失的半裸露海滩（3）受遮挡的短海滩，其净沉积物变化和海滩响应的沿岸变化有限;（4）有遮蔽的长海滩，其海滩响应沿岸变化较大，总沉积物变化较大，但净沉积物变化有限。确定海滩响应类型的关键因素是：暴露于风暴波、风暴波接近的角度和海滩的入湾程度。这些因素普遍适用于世界各地的许多暴露的海岸线，因此，这里提出的响应分类，预计将广泛适用。
Extreme storms are responsible for rapid changes to coastlines worldwide. During the 2013/14 winter, the west coast of Europe experienced a sequence of large, storm-induced wave events, representing the most energetic period of waves in the last 60 years. The southwest coast of England underwent significant geomorphological change during that period, but exhibited a range of spatially variable and complex morphological responses, despite being subjected to the same storm sequence. Here, we use the 2013/14 storm response along the southwest coast of England as a natural field laboratory and explain this variability in storm response through the introduction and evaluation of a new classification of how sandy and gravel beaches respond to extreme storms. Cluster analysis was conducted using an unique data set of pre- and post-storm airborne Light Detection and Ranging (LiDAR) data from 157 beach sites based on the net volumetric change (dQnet) and a novel parameter, the longshore variation index (LVI) which quantifies the alongshore morphological variability in beach response. Four main beach response types were identified: (1) fully exposed beaches that experienced large and alongshore uniform sediment losses (dQnet≈ 100 m3·m− 1); (2) semi-exposed beaches that experienced medium alongshore uniform sediment losses (dQnet≈ 50 m3·m− 1); (3) sheltered short beaches that experienced limited net sediment change and alongshore variability in beach response; and (4) sheltered long beaches that experienced considerable alongshore variability in beach response and large gross sediment change, but limited net sediment change. The key factors in determining the type of beach response are: exposure to the storm waves, angle of storm wave approach and the degree to which the beach is embayed. These factors are universally applicable on many exposed coastlines worldwide, so the response classification presented here is expected to be widely applicable.