Developing capacity for planning and adapting to riverbank erosion and its consequences in the Yukon River Basin

导航新北极（NNA）是美国国家科学基金会的十大构想之一。NNA项目解决快速变化的北极地区的融合科学挑战。北极研究需要为国家、更大地区和全球的经济、安全和复原力提供信息。NNA支持从地方到国际规模的新研究伙伴关系，使下一代北极研究人员多样化，加强正式和非正式教育的努力，并在适当情况下整合知识的共同生产。该奖项通过解决以下NNA重点领域的社会系统、自然环境和建筑环境之间的相互作用，实现了这一目标的一部分：北极居民、数据和观测、预测、全球影响和弹性基础设施。北极变暖正在导致影响北极社区的景观变化。河流和洪泛平原特别容易受到气候变暖的影响，因为永久冻土解冻会加速侵蚀。这种侵蚀威胁着关键的基础设施，扰乱了社区生活，有时甚至会取代整个阿拉斯加社区。然而，侵蚀对气候变暖的反应及其影响还没有得到很好的理解。除了危及基础设施之外，侵蚀还暴露了冰冻的洪泛区沉积物，其中含有潜在的污染物，包括重金属，如汞，以及营养物质和病原体，所有这些都可能危及水质和生态系统的健康。通过影响社区基础设施和水质，北极河流侵蚀是影响社会的多种问题的纽带。更好地了解河岸侵蚀及其对水质的影响对于支持北极社区的可持续发展至关重要。同样重要的是了解区域适应能力的挑战和机遇，以便将科学知识纳入可操作的计划和政策。为了应对这些对科学知识和社会重要的多重挑战，该项目联合了来自育空河部落间流域委员会、阿拉斯加安克雷奇大学、加州理工学院、洛斯阿拉莫斯国家实验室、南加州大学的研究小组，以及育空河流域受到河岸侵蚀威胁的三个土著合作社区。该项目将开发景观演变的数值模型，以了解变暖的北极地区河岸侵蚀的速度及其对影响水质和社区基础设施的生物地球化学过程的影响。观测站将监测河岸侵蚀、水流水力学、水质和微生物生态系统，这三个研究地点与育空河流域的伙伴社区位于同一地点。漫滩、河岸和水柱采样将与生物地球化学、同位素和宏基因组测量一起使用，以了解细沉积物、营养物质、汞和其他金属以及病原体的丰度、特征和过程动态。该项目还将包括评估区域适应能力和确定适应的机会和体制障碍。自然科学和社会科学将汇集在一起，制定阿拉斯加土著社区为适应气候变化所需要的侵蚀行动计划。以社区为基础的科学将加强这种合作努力，与伙伴社区的教育活动将建立和加强对过程的理解。基于网络的模块将说明并告知公众北极河流的观测变化、未来预测，以及新科学如何与公民科学努力相结合，从而为可持续的北极社区制定有效的规划战略。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Navigating the New Arctic (NNA) is one of NSF's 10 Big Ideas. NNA projects address convergence scientific challenges in the rapidly changing Arctic. The Arctic research is needed to inform the economy, security and resilience of the Nation, the larger region and the globe. NNA empowers new research partnerships from local to international scales, diversifies the next generation of Arctic researchers, enhances efforts in formal and informal education, and integrates the co-production of knowledge where appropriate. This award fulfills part of that aim by addressing interactions among social systems, natural environment, and built environment in the following NNA focus areas: Arctic Residents, Data and Observation, Forecasting, Global Impact, and Resilient Infrastructure. Arctic warming is causing landscape change that is affecting Arctic communities. Rivers and floodplains are particularly susceptible to a warmer climate due to permafrost thaw that can lead to accelerated erosion. This erosion threatens critical infrastructure and disrupts community life, including by sometimes displacing entire Alaska communities. Yet the response of erosion to warming, and its implications, are not well understood. In addition to imperiling infrastructure, erosion exposes frozen floodplain sediment that contains potential contaminants including heavy metals, such as mercury, along with nutrients and pathogens, all of which can imperil water quality and ecosystem health. By affecting community infrastructure and water quality, Arctic river erosion sits at the nexus of multiple problems that impact society. Greater understanding of bank erosion and its water quality impacts will be critical to supporting sustainable Arctic communities. Equally important will be understanding regional adaptive capacity challenges and opportunities to allow for the adoption of scientific knowledge into actionable plans and policies. To meet these multiple challenges important for scientific knowledge and society, this project unites a research team from the Yukon River Inter-Tribal Watershed Council, University of Alaska Anchorage, California Institute of Technology, Los Alamos National Laboratory, University of Southern California, and three Indigenous partner communities in the Yukon River basin that are threatened by riverbank erosion.The project will develop numerical models of landscape evolution to understand rates of riverbank erosion in the warming Arctic and their effects on biogeochemical processes that affect water quality and community infrastructure. Observational stations will monitor bank erosion, flow hydraulics, water quality and microbial ecosystems at three study sites co-located with partner communities in the Yukon River basin. Floodplain, riverbank and water column sampling will be used with biogeochemical, isotopic and metagenomic measurements to understand the abundance, character and process dynamics of fine sediment, nutrients, mercury and other metals, and pathogens. The project also will include an evaluation of regional adaptive capacity and an identification of opportunities for and institutional barriers to adaptation. Natural and social science will converge to produce Erosion Action Plans that are needed for Alaska Native communities to plan for climate-change adaptation. Community-based science will enhance this collaborative effort, and educational activities with our partner communities will build and fortify process understanding. Web-based modules will illustrate and inform the public about observed changes in Arctic rivers, future projections, and how new science combined with citizen-science efforts can lead to effective planning strategies for sustainable Arctic communities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.