Arctic-subarctic coastal hazards and morphodynamics (AsCHMor)

沿海风暴以不同的规模塑造海岸线，每年影响数百万人。尽管在南方国家进行了广泛的研究，但对北极地区的风暴影响仍然知之甚少，因为高频测量在偏远海岸几乎不可行。然而，沿海变化正在影响因纽特人社区，并且因永久冻土融化和海冰减少而加剧。后者进一步有助于增加波高。北极和亚北极地区的极端沿海事件可能是由开放水域或冰覆盖水域的高水位和波浪共同引起的。低温过程和危害涉及海冰冻结/破裂、冻融循环和冰推脊。整个北极地区不同的均衡调整也会导致海平面变化的对比，从而模糊了海岸侵蚀和洪水的影响。我们假设冰冻沉积物也控制着沿海过度冲刷过程，这是沿海管理的主要关注点。因此，在冰冻海岸，预测海岸的长期演变并非易事。 北极-亚北极海岸灾害和形态动力学（AsCHMor）研究计划的目标是显着提高我们对北极-亚北极地区海岸形态动力学的理解，并提高我们在气候变化和人类对海岸压力增加的影响下模拟和预测未来海岸行为的能力。该计划针对的是北极地区很少探索的沿海灾害的两个组成部分。首先，将实施 AsCHMor (i) 以更好地了解加拿大北部社区强风暴期间海滩沉积物渗透性与冲刷带孔隙冰饱和度之间的复杂相互作用。 (ii) 第二个组成部分整合了区域和地方尺度上冰冻水域沿海总水位的经验/数值模型的探索和应用，以提高我们的风险管理能力。 AsCHMor 将通过大量的观测、建模和技术开发在整个迭代过程中实施。 11 个 HQP（5 名理学士、4 名理学硕士、2 名博士）将在亚北极和高北极沿海社区（圣劳伦斯河口、哈德逊湾、琼斯湾）开展实地工作。利用我之前的工作，将部署与国内和国际合作者设计的新颖的岸基视频网络。该提案是独特的，对于改善北极沿海动态和灾害的知识差距是必要的。它的实施将为快速发生的沿海灾害情况提供新的预测工具，从而使北部社区受益。它将通过科学研究和监测增加社区决策的自主权。 AsHCMor 的长期目标是加强加拿大北部的预报服务和早期预警，并为北部社区的疏散和适应策略提供有效的时间信息。

Coastal storms shape coastlines at various scales and affect millions of people annually. Although widely studied in southern countries, storm impacts are still poorly understood in the Arctic because high-frequency measurements are hardly feasible on remote coasts. Coastal changes are nevertheless affecting Inuit communities, and are enhanced by permafrost thaw and sea ice reduction. The latter further contributes to increased wave heights. Extreme coastal events in arctic and subarctic regions are presumably caused by combined high water levels and waves, either under open or ice-infested waters. Cryogenic processes and hazards involve sea ice freeze/break-up, freeze-thaw cycles, and ice push ridges. Varying isostatic adjustments throughout the Arctic also result in contrasting sea-level variations that blur the impacts of coastal erosion and flooding. We hypothesize that frozen sediments also controls coastal overwash processes, and this is a primary concern for coastal management. On frozen coasts, it is therefore not trivial to predict coastal evolution in the long term. The objective of the Arctic-subarctic coastal hazards and morphodynamics (AsCHMor) research program is to significantly improve our understanding of coastal morphodynamics in the arctic-subarctic region and to enhance our capacity to simulate and predict future coastal behaviors under the impacts of climate change and increasing human pressure on the coast. The program targets two components of coastal hazards rarely explored in the Arctic. First, AsCHMor will be implemented (i) to better understand the complex interactions between beach sediment permeability and pore-ice saturation in the swash zone during energetic storms in northern Canadian communities. (ii) The second component integrates the exploration and application of empirical/numerical models of coastal total water levels in ice-infested waters at both regional and local scales to improve our risk management capacity. AsCHMor will be implemented throughout an iterative process using numerous observational, modeling, and technological development. Eleven HQP (5 B.Sc., 4 M.Sc., 2 Ph.D.) will perform field works on subarctic and High Arctic coastal communities (St. Lawrence Estuary, Hudson Bay, Jones Sound). Capitalizing on my previous works, a novel shore-based video network designed with national and international collaborators will be deployed. This proposal is unique and necessary to improve knowledge gaps in Arctic coastal dynamics and hazards. Its implementation will benefit northern communities by providing new predictive tools on fast-onset coastal disasters situations. It will increase autonomy in community decision-making through scientific research and monitoring. The long-term goal of AsHCMor is to strengthen Canada's forecasting services and early warnings in the north and to provide efficient information on time for evacuation and adaptation strategies in northern communities.