Numerical modeling of the impact of sea-level rise on fringing coral reef hydrodynamics and sediment transport
Numerical modeling of the impact of sea-level rise on fringing coral reef hydrodynamics and sediment transport
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DOI：
10.1007/s00338-011-0723-9
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发表时间：
2011-06-01
期刊：
影响因子：
3.5
通讯作者：
Presto, M. K.
中科院分区：
文献类型：
--
作者：
Storlazzi, C. D.;Elias, E.;Presto, M. K.
大多数气候预测表明，到2100年，海平面可能上升0.5-1.0米;然而，目前尚不清楚，暴露的边缘珊瑚礁上的流体流动和沉积物动力学可能会因海平面迅速上升而发生何种变化。耦合水动力和沉积物输运数值模拟与最近发表的结果一致，表明在1-2米深的暴露边缘礁坪上增加0.5-1.0米的水深将导致更大的波高和设置，进一步提升礁坪上的水深。较大的波浪会产生较高的近床剪切应力，这反过来又会导致沉积物的大小和数量增加，这些沉积物可以从海底重新悬浮或从邻近的沿海平原沉积物中侵蚀出来。随着水深的增加，波浪和风力驱动的水流会更大，增加了从内礁坪到外礁坪和珊瑚生长最多的前礁的水和沉积物的沿岸和近海通量。沉积物在边缘礁坪上的停留时间，随着海平面上升的幅度接近礁坪的平均水深，随着海平面上升呈指数下降。这里提出的模型结果表明，海平面上升0.5-1.0米可能会增加海岸侵蚀，混合和循环，沉积物再悬浮的量，以及暴露的礁滩高浊度的持续时间，导致光合作用的光可用性降低，增加沉积物引起的压力对珊瑚礁生态系统，并可能影响其他一些生态过程。
Most climate projections suggest that sea level may rise on the order of 0.5-1.0 m by 2100; it is not clear, however, how fluid flow and sediment dynamics on exposed fringing reefs might change in response to this rapid sea-level rise. Coupled hydrodynamic and sediment-transport numerical modeling is consistent with recent published results that suggest that an increase in water depth on the order of 0.5-1.0 m on a 1-2 m deep exposed fringing reef flat would result in larger significant wave heights and setup, further elevating water depths on the reef flat. Larger waves would generate higher near-bed shear stresses, which, in turn, would result in an increase in both the size and the quantity of sediment that can be resuspended from the seabed or eroded from adjacent coastal plain deposits. Greater wave- and wind-driven currents would develop with increasing water depth, increasing the alongshore and offshore flux of water and sediment from the inner reef flat to the outer reef flat and fore reef where coral growth is typically greatest. Sediment residence time on the fringing reef flat was modeled to decrease exponentially with increasing sea-level rise as the magnitude of sea-level rise approached the mean water depth over the reef flat. The model results presented here suggest that a 0.5-1.0 m rise in sea level will likely increase coastal erosion, mixing and circulation, the amount of sediment resuspended, and the duration of high turbidity on exposed reef flats, resulting in decreased light availability for photosynthesis, increased sediment-induced stress on the reef ecosystem, and potentially affecting a number of other ecological processes.