Sediment resuspension and transport patterns on a fringing reef flat, Molokai, Hawaii
Sediment resuspension and transport patterns on a fringing reef flat, Molokai, Hawaii
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DOI：
10.1007/s00338-004-0415-9
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发表时间：
2004-07
期刊：
影响因子：
3.5
通讯作者：
A. Ogston;C. Storlazzi;M. E. Field;M. Presto
中科院分区：
文献类型：
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作者：
A. Ogston;C. Storlazzi;M. E. Field;M. Presto
众所周知，珊瑚在世界各地的各种浑浊环境中蓬勃发展。珊瑚生境中清水和浊水之间的定量区别没有很好的界定，用来评价珊瑚礁环境状况的悬浮泥沙量和沉降率也没有很好的确定。这项研究的沉积物再悬浮，运输，并导致沉积物上的边缘礁坪莫洛凯岛，夏威夷，使用一年的时间序列数据从一个小的，仪器化的三脚架。它显示了信风和海浪高度在控制沉积物运动方面的重要性。沉积物通常每天重新悬浮，控制事件规模（10-25毫克/升）的主要因素是信风产生的波浪和水流以及礁滩的潮汐高度。该礁沉积物的净通量主要是沿着礁坪的盛行信风方向（向西），其次是轻微离岸方向，朝向珊瑚丰度低的区域。这些结果在几个方面适用于其他地区的礁研究和礁管理。首先，所观察到的再悬浮和浑浊的细颗粒陆源沉积物，似乎被困在礁坪和回收的结果。因此，珊瑚受到光衰减由相同的颗粒反复，但小的数量。其次，测量结果显示沉积物再悬浮的时间变化（从每日到季节尺度）很大，这表明单次测量不足以准确描述礁滩的条件。
Corals are known to flourish in various turbid environments around the world. The quantitative distinction between clear and turbid water in coral habitats is not well defined nor are the amount of sediment in suspension and rates of sedimentation used to evaluate the condition of reef environments well established. This study of sediment resuspension, transport, and resulting deposition on a fringing reef flat off Molokai, Hawaii, uses a year of time-series data from a small, instrumented tripod. It shows the importance of trade winds and ocean wave heights in controlling the movement of sediment. Sediment is typically resuspended daily and the dominant controls on the magnitude of events (10–25 mg/l) are the trade-wind-generated waves and currents and tidal elevation on the reef flat. The net flux of sediment on this reef is primarily along the reef flat in the direction of the prevailing trade winds (to the west), with a secondary direction of slightly offshore, towards a zone of low coral abundance.These results have application to reef studies and reef management in other areas in several ways. First, the observed resuspension and turbidity results from fine-grained terrigenous sediment that appears to be trapped and recycled on the reef flat. Thus corals are subjected to light attenuation by the same particles repeatedly, however small the amount. Secondly, the measurements show high temporal variability (from daily to seasonal scales) of sediment resuspension, indicating that single measurements are inadequate to accurately describe conditions on a reef flat.