A rules-based shoreface translation and sediment budgeting tool for estimating coastal change: ShoreTrans
A rules-based shoreface translation and sediment budgeting tool for estimating coastal change: ShoreTrans
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DOI：
10.1016/j.margeo.2021.106466
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发表时间：
2021-04-07
期刊：
影响因子：
2.9
通讯作者：
Davidson, Mark
中科院分区：
文献类型：
--
作者：
McCarroll, R. Jak;Masselink, Gerd;Davidson, Mark
随着海平面上升（SLR）的加速，预测全球海岸线的变化提出了越来越大的挑战。许多海岸线预测模型使用简单的“布鲁恩规则”来处理SLR剖面转换，部分原因是替代方法过于复杂和耗时。为了解决这个问题，我们介绍ShoreTrans：一个简单的，基于规则的，用户输入驱动的，shoreface翻译和沉积物预算模型，适用于调查的2D剖面（不是参数化），估计变化的现实海岸线，造成SLR和沉积物供应的变化，同时考虑装甲，硬岩悬崖和露头岩石。该工具可适用于10-100年时间尺度的砂、砾石、岩石和工程海岸，考虑到海岸线的趋势和变化。该方法考虑到：（1）沙丘侵蚀/加积;（2）屏障回滚;（3）不可侵蚀层;（4）海堤;（5）下滨面搬运;（6）沿岸旋转;（7）其他源和汇。使用输入的概率分布和蒙特卡罗模拟来解释不确定性。我们提供了一个第一次通过评估的两个macrotidate英国海湾：Perranporth（桑迪，耗散，跨海岸占主导地位的运输）和启动湾（砾石，反射，双向alongshore占主导地位），然后使用理想化的配置文件，调查强制控制海岸线衰退和海滩宽度的相对重要性。对于耗散的桑迪网站，海岸变化的主要模式是短期的风暴侵蚀和SLR的翻译，而长期的趋势可能是重要的，但高度不确定的。对于反射砾石场地，主要模式是多年代际沿岸沉积物通量，而短期沿岸旋转和SLR平移是次要的。相对于ShoreTrans方法，Bruun规则低估了悬崖、海堤和回滚的低屏障前的海岸线衰退，并高估了存在大型可侵蚀沙丘的地方。ShoreTrans直接解决了海滩宽度的变化，预计海堤和悬崖前的海滩将缩小，因此狭窄的海滩（
Predicting change to shorelines globally presents an increasing challenge as sea level rise (SLR) accelerates. Many shoreline prediction models use the simplistic 'Bruun rule' for dealing with SLR profile translation, in-part due to alternative approaches being too complex and time-consuming to implement. To address this, we introduce ShoreTrans: a simple, rules-based, user-input driven, shoreface translation and sediment budgeting model, that applies the surveyed 2D-profile (not a parameterization), for estimating change to realistic coastlines, resulting from SLR and variations in sediment supply, while accounting for armouring, hard-rock cliffs and outcropping rocks. The tool can be applied to sand, gravel, rock and engineered coasts at a temporal scale of 10-100 years, accounting for shoreline trends as well as variability. The method accounts for: (1) dune encroachment/accretion; (2) barrier rollback; (3) non-erodible layers; (4) seawalls; (5) lower shoreface transport; (6) alongshore rotation; and (7) other sources and sinks. Uncertainty is accounted for using a probabilistic distribution for inputs and Monte Carlo simulations. We provide a first-pass assessment of two macrotidal UK embayments: Perranporth (sandy, dissipative, cross-shore dominant transport) and Start Bay (gravel, reflective, bi-directional alongshore dominant), then use idealised profiles to investigate the relative importance of forcing controls on shoreline recession and beach width. For the dissipative sandy site, the primary modes of coastal change are predicted to be short-term storm erosion and SLR translation while long-term trends may be important but are highly uncertain. For the reflective gravel site, the primary mode is multi-decadal longshore sediment flux, while short-term alongshore rotation and SLR translation are secondary. Relative to the ShoreTrans approach, the Bruun rule under-predicts shoreline recession in front of cliffs, seawalls and for low barriers that rollback, and over-predicts where large erodible dunes are present. ShoreTrans directly addresses change in beach width, with beaches in front of seawalls and cliffs predicted to shrink, such that narrow beaches (