The influence of alongshore and cross‐shore wave energy flux on large‐ and small‐scale coastal erosion patterns
The influence of alongshore and cross‐shore wave energy flux on large‐ and small‐scale coastal erosion patterns
复制标题
近岸和跨岸波浪能量通量对大、小规模海岸侵蚀模式的影响
DOI：
10.1002/esp.2125
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
S. Takewaka
中科院分区：
文献类型：
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作者：
E. Galal;S. Takewaka
2006年10月，一个强大的低压系统沿日本本州岛移动。大浪和风暴潮袭击了鹿岛海岸，造成该地区大面积侵蚀。分析了2005年10月和2006年11月测量的机载激光数据，以估计地面区域内的横截面变化。横截面积变化的沿岸分布结果表明，北段38 km长、南段15 km长侵蚀量各向南递减，有人工岬角的保护区侵蚀量小于无保护地。侵蚀和吸积模式的局部沿岸变化表现为数百米的波浪起伏。北段和南段陆地区域的总侵蚀量分别为62万m3和60万m3。采用模拟近岸波浪（SWAN）模型对风暴期间沿岸的波浪状况进行了估计。对计算结果进行了验证，并将波浪能沿岸分布（表示为波浪能通量的沿岸和跨岸分量）与横截面变化的沿岸分布进行了比较。结果表明，能量通量的分布能很好地解释侵蚀的分布：侵蚀的大尺度变化是由跨岸能量通量的沿岸变异性引起的，而短尺度变化是由沿岸能量通量的梯度引起的，特别是在没有海岸工程的地区。版权所有©2011 John Wiley & Sons， Ltd
A strong low‐pressure system traveled along the Japanese main island Honshu in October 2006. High waves and storm surge attacked the Kashima Coast resulting in huge erosion over the area. Airborne laser data measured in October 2005 and November 2006 were analyzed to estimate cross‐sectional changes within the subaerial zone. The results of the alongshore distribution of the changes of cross‐sectional area indicate that the amount of erosion of the 38 km‐long northern and 15 km‐long southern parts decreased toward the south in each part and that the amount of erosion was smaller in protected areas with artificial headlands than in unprotected areas. The local alongshore variation of the erosion and accretion patterns showed wavy fluctuations of several hundreds of meters. The total amounts of the estimated eroded volume of the subaerial zone over the northern and southern parts were 620 000 m3 and 600 000 m3, respectively. The Simulating Waves Nearshore (SWAN) wave model was applied to estimate wave conditions along the coast during the storm. The computational results were verified, and then the alongshore distribution of wave energies, expressed as the alongshore and cross‐shore components of the wave energy flux, was compared with the alongshore distribution of cross‐sectional change. The results show that the distribution of energy flux explains the distribution of erosion well: The alongshore variability in the cross‐shore energy flux is responsible for the large‐scale variability in erosion, and shorter‐scale variability is due to gradients in the alongshore energy fluxes, especially for the areas without coastal works. Copyright © 2011 John Wiley & Sons, Ltd.