Modelling and Assessing Surge Wave Impacts on Hydrodynamic Mixing and Transport

海啸、洪水和风暴潮等极端自然事件是极具破坏性的现象，对人类健康和生态系统产生不利影响。此外，海啸和风暴活动也将随着气候变化而发生变化（在强度和频率方面）。在大型沿海风暴期间，浪涌波引起显著的地貌变化，并促使污染物和碎片从陆地转移到水中。也就是说，2011年东日本大地震后的海啸将大量的陆地垃圾推入海洋，相当于日本海岸线数千年的正常垃圾。涌浪具有瞬时和前所未有的性质。涌浪的一个重要特征是水面在空间和时间上的快速变形。波浪的传播和破碎在波阵面附近产生强烈的湍流。湍流特性、自由表面变形和大量夹带空气之间的相互作用决定了涌浪中混合和输运的动力学。数值和实验建模扩展了我们的能力，准确地预测在可持续发展的背景下，这些水文灾害的潜在风险。建议的研究计划，提高了我们的理解浪涌诱导混合和湍流。我们的目标是开发和实施计算和实验技术，以收集与各种湍流机制，如剪切层，波浪破碎，流向平流二次流相关的详细证据。确定占主导地位的湍流状态将有助于我们调查浪涌引起的运输及其对碎片和污染物的再分布的影响。 人们越来越关注气候变化对天气、降水模式以及对海啸和巨浪强度的影响。为了设计具有复原力的社区，并解决此类事件期间的社会和生态系统脆弱性，必须了解水患的详细水动力行为及其与周围环境的相互作用。这项研究的结果将有助于我们预测和减轻日益普遍的水文灾害对湍流混合和运输的自然模式的影响。

Extreme natural events such as tsunamis, floods, and storm surges are highly destructive phenomena that adversely impact human health and ecosystem. Moreover, tsunamic and storm activities will undergo changes (in terms of their intensity and frequency) associated with climate change. During large coastal storms, surge waves induce significant landscape changes and prompt the transport of contaminants and debris from land to water. Namely, the tsunami after the Great East Japan Earthquake in 2011 pushed a vast amount of in-land debris into the ocean, equivalent to thousands of years of normal litter from Japan's coastline. Surge waves have a transient and unprecedented nature. One of the key features of the surge waves is the rapid spatial and temporal deformations of the water's free-surface. Wave propagation and its breaking create intense turbulent flow in the vicinity of the wave's front. The interplay between turbulent properties, free-surface deformation, and large quantities of entrained air governs the dynamics of mixing and transport in surge waves. Numerical and experimental modeling expand our capability to accurately predict the potential risks of these hydro-hazards in the context of sustainable development. The proposed research program enhances our understanding of surge-induced mixing and turbulence. We aim to develop and implement computational and experimental techniques to gather detailed evidence associated with various turbulence mechanisms, such as shear layer, wave breaking, and streamwise advective secondary flows. Identifying the dominant turbulent flow regimes will help us investigate the surge-induced transport and its implications on redistribution of debris and contaminants. There are rising concerns over the impacts of climate change on weather, precipitation patterns, and on the intensity of tsunami and surge waves. In order to design resilient communities and address the social and ecosystem vulnerability during such events, it is critical to understand the detailed hydrodynamic behaviour of hydro-hazards and their interactions with their surrounding environment. The outcome of this research will help us anticipate and mitigate the impacts of increasingly prevalent hydro-hazards on natural patterns of turbulent mixing and transport.