Field study of wave attenuation on an offshore coral reef
Field study of wave attenuation on an offshore coral reef
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DOI：
10.1029/96jc00202
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发表时间：
1996-06-15
影响因子：
3.6
通讯作者：
Young, IR
中科院分区：
文献类型：
--
作者：
Hardy, TA;Young, IR
进行了一项主要的现场实验，测量了短重力波穿过近海珊瑚礁迎风边缘时的衰减和转化。在各种环境条件下，收集了3000多个单独时间序列的水位数据。在最内侧的测量点，即位于水平礁坪上的波浪破碎完成后，有效波高和最大波高的上限被限制在小于40%和60%的礁坪水深，分别。与有意义的波高一样，礁滩谱的形状和能量水平受到礁滩水深变化的强烈影响。高潮位时，礁坪上的谱与入射谱非常接近，但低频和高能谱的衰减都较大，这就导致礁坪上的谱比礁迎风面上的谱宽。在较低的水位，由于波浪破碎和底部摩擦发生相当大的能量损失。大部分的能量损失来自于谱峰附近，并且可以看到能量向谱峰的谐波偏移。
A major field experiment was conducted which obtained measurements of the attenuation and transformation of short gravity waves as they cross the windward edge of an offshore coral reef. Water level data were collected for over 3000 individual time series during a wide range of environmental conditions. At the innermost measurement site, which is located on the horizontal reef flat after the completion of wave breaking, the upper bound of significant and maximum wave heights is limited to less than 40% and 60% of the reef flat water depth, respectively. As with significant wave height, both the shape and energy level of the reef flat spectra are strongly affected by changes in reef nat water depth. For higher tide levels the spectra on the reef flat closely mimic the corresponding incident spectra, However, the attenuation is greater for both lower frequencies and higher-energy portions of the spectra, This causes the reef flat spectra to be broader than those measured windward of the reef. At lower water levels, considerable energy losses due to wave breaking and bottom friction occur. Most of the energy loss comes from the vicinity of the spectral peak, and energy shifts to harmonics of the peak of the spectrum can be seen.