Appropriate complexity for the prediction of coastal and estuarine geomorphic behaviour at decadal to centennial scales
Appropriate complexity for the prediction of coastal and estuarine geomorphic behaviour at decadal to centennial scales
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DOI：
10.1016/j.geomorph.2015.10.005
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发表时间：
2016-03-01
期刊：
影响因子：
3.9
通讯作者：
Cowell, Peter
中科院分区：
文献类型：
--
作者：
French, Jon;Payo, Andres;Cowell, Peter
沿海和河口地貌提供了一个物理模板，不仅可以容纳不同的生态系统功能和人类活动，而且还可以调解预计随着气候变化而增加的洪水和侵蚀风险。在本文中，我们探讨了一些与沿海形态变化的概念化和建模在时间和空间尺度相关的管理者和政策制定者的问题。首先，我们重新审视的问题，如何确定最适当的尺度，在寻求定量预测的地貌变化的年龄范围内，由人类干扰自然沉积系统和气候和海洋强迫的重大变化的前景。其次，我们考虑的理论基础和概念框架，以确定哪些过程是最重要的，在一个给定的规模的利益和相关的问题，如何将这种理解转化为计算上可行的模型，保留一个良好的物理基础，并表现出有用的预测技能。特别是，我们探讨了一个主要的尺度方法的局限性，并在何种程度上可以解决的沿海地带的概念和系统理论的应用。第三，我们认为不同风格的地貌变化的重要性和需要解决不仅增量形态的演变，但也在一个系统和/或其总形态配置的定性动态变化。地貌系统的极端复杂性和空间分布的性质意味着，对未来变化的定量预测必须通过某种形式的机械建模来实现。地貌学越来越多地接受所谓的“简化复杂性”模型作为一种手段，从一个基本上是还原论的重点，对地形演变的机制，泥沙输移到一个更综合的观点。然而，关于什么是降低复杂性模型的共识很少，而且这个术语本身既有误导性，也毫无帮助。因此，我们综合了一套要求，可以称之为“适当的复杂性模拟”的定量海岸形态变化的规模与当代管理和决策的要求：1）被研究的系统必须是有界的参考时间和空间尺度上的利益行为出现和/或科学或管理问题的出现;（2）模型的复杂性和全面性必须适合当前的问题;（3）建模者应寻求先验的见解，了解在感兴趣的规模上什么样的行为可能是明显的，以及模型的行为有效性在多大程度上可能受到其基本假设和全面性的限制; 4）通过对可能的动态行为的定性了解，然后应制定模型，以解决关键的状态变化; 5）沿海形态变化的中尺度建模应批判性地反映建模的作用及其与可观察世界的关系。(C)2015年由Elsevier B. V.出版
Coastal and estuarine landforms provide a physical template that not only accommodates diverse ecosystem functions and human activities, but also mediates flood and erosion risks that are expected to increase with climate change. In this paper, we explore some of the issues associated with the conceptualisation and modelling of coastal morphological change at time and space scales relevant to managers and policy makers. Firstly, we revisit the question of how to define the most appropriate scales at which to seek quantitative predictions of landform change within an age defined by human interference with natural sediment systems and by the prospect of significant changes in climate and ocean forcing. Secondly, we consider the theoretical bases and conceptual frameworks for determining which processes are most important at a given scale of interest and the related problem of how to translate this understanding into models that are computationally feasible, retain a sound physical basis and demonstrate useful predictive skill. In particular, we explore the limitations of a primary scale approach and the extent to which these can be resolved with reference to the concept of the coastal tract and application of systems theory. Thirdly, we consider the importance of different styles of landform change and the need to resolve not only incremental evolution of morphology but also changes in the qualitative dynamics of a system and/or its gross morphological configuration. The extreme complexity and spatially distributed nature of landform systems means that quantitative prediction of future changes must necessarily be approached through mechanistic modelling of some form or another. Geomorphology has increasingly embraced so-called 'reduced complexity' models as a means of moving from an essentially reductionist focus on the mechanics of sediment transport towards a more synthesist view of landform evolution. However, there is little consensus on exactly what constitutes a reduced complexity model and the term itself is both misleading and, arguably, unhelpful. Accordingly, we synthesise a set of requirements for what might be termed 'appropriate complexity modelling' of quantitative coastal morphological change at scales commensurate with contemporary management and policy -making requirements: 1) The system being studied must be bounded with reference to the time and space scales at which behaviours of interest emerge and/or scientific or management problems arise; 2) model complexity and comprehensiveness must be appropriate to the problem at hand; 3) modellers should seek a priori insights into what kind of behaviours are likely to be evident at the scale of interest and the extent to which the behavioural validity of a model may be constrained by its underlying assumptions and its comprehensiveness; 4) informed by qualitative insights into likely dynamic behaviour, models should then be formulated with a view to resolving critical state changes; and 5) meso-scale modelling of coastal morphological change should reflect critically on the role of modelling and its relation to the observable world. (C) 2015 Published by Elsevier B.V.