Complex coastlines responding to climate change: do shoreline shapes reflect present forcing or “remember” the distant past?
Complex coastlines responding to climate change: do shoreline shapes reflect present forcing or “remember” the distant past?
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应对气候变化的复杂海岸线：海岸线形状反映了当前的强迫还是“记住”了遥远的过去？
DOI：
10.5194/esurf-4-871-2016
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发表时间：
2016
影响因子：
2.9
通讯作者：
M. Ellis
中科院分区：
文献类型：
--
作者：
C. Thomas;A. Murray;A. Ashton;M. Hurst;A. Barkwith;M. Ellis
一系列的平面形态形态出现沿着桑迪海岸线作为离岸波浪气候的功能。它已隐含假设的形态响应时间是快速的相比，波浪气候变化的时间尺度，这意味着海岸形态简单地反映了现存的波浪气候。这一假设已经探讨了两个独特的形态海岸线的响应-飞行嘴和尖角海角-不断变化的波浪气候，使用海岸线演变模型。结果表明，先决条件是重要的，在确定的演变形态，和桑迪海岸线可以表现出滞后行为。特别是，先行形态是特别重要的飞行吐的演变，与特征的时间尺度的形态调整的顺序为几个世纪的大吐。特征时间尺度随海角和沙嘴长宽比的平方而变化;沙嘴的时间尺度比海角长一个数量级（几百年或几十年）。当波浪气候的变化比相关的特征时间尺度更慢时，海岸线能够以准平衡的方式进行调整。我们的研究结果有重要的影响，管理的桑迪海岸线的决定可能是隐含的和不正确的假设，即现今的海岸线与当前的条件是平衡的。
A range of planform morphologies emerge along sandy coastlines as a function of offshore wave climate. It has been implicitly assumed that the morphological response time is rapid compared to the timescales of wave climate change, meaning that coastal morphologies simply reflect the extant wave climate. This assumption has been explored by focussing on the response of two distinctive morphological coastlines – flying spits and cuspate capes – to changing wave climates, using a coastline evolution model. Results indicate that antecedent conditions are important in determining the evolution of morphologies, and that sandy coastlines can demonstrate hysteresis behaviour. In particular, antecedent morphology is particularly important in the evolution of flying spits, with characteristic timescales of morphological adjustment on the order of centuries for large spits. Characteristic timescales vary with the square of aspect ratios of capes and spits; for spits, these timescales are an order of magnitude longer than for capes (centuries vs. decades). When wave climates change more slowly than the relevant characteristic timescales, coastlines are able to adjust in a quasi-equilibrium manner. Our results have important implications for the management of sandy coastlines where decisions may be implicitly and incorrectly based on the assumption that present-day coastlines are in equilibrium with current conditions.
在颈部、烤叉上：控制自由烤叉的形状
影响因子：
3.4
作者：
Ashton, A. D.;Nienhuis, J.;Ells, K.
通讯作者：
Ells, K.