Collaborative Research: Predicting riverbank erosion in thawing permafrost

合作研究：预测永久冻土融化中的河岸侵蚀

• 批准号: 2031532
• 负责人: Michael Lamb
• 金额: $ 46.57万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2031532&HistoricalAwards=false
• 关键词: Collaborative; Research; Predicting; riverbank; erosion

Most Arctic floodplains have permanently frozen subsoil, or permafrost, that keeps the land intact and habitable along coasts and riverbanks. However, permafrost thaw can lead to widespread destabilization of the land and enhanced riverbank erosion. This erosion threatens critical infrastructure that is vital to national prosperity and security, and has led to the displacement of entire Alaskan communities. The main objective of this proposal is to develop and test a mathematical theory for riverbank erosion in permafrost. The theory will be tested using novel indoor permafrost-river experiments at the Caltech Earth Surface Dynamics Laboratory, and through measurements along the Koyukuk River, AK, in collaboration with the Native Alaskan community of Huslia. The work promises to fill a gap in our basic understanding of how river systems respond to global warming. In addition, it will contribute to climate-change adaptation planning for riverside communities in the Yukon River watershed. The next generation of scientists will be trained at the undergraduate and PhD levels in integrated hazard assessment by bringing together community engagement and basic and applied science to address an environmental crisis with both local and global implications. The main objective of this proposal is to develop and test a thermo-mechanical model for river-bank erosion in permafrost. In addition to seeking to understand the basic mechanics of bank erosion in cold environments, the model will be used to quantitatively assess how bank erosion rates will respond to climate change. The model will be tested against flume experiments specially designed to span the range of permafrost river characteristics and to test hypotheses related to river flow velocity, river water temperature, and bank sediment grain size. Measurements of hydraulic, mechanical and thermal properties of cutbanks along the Koyukuk River, Alaska, will be used to evaluate the model for entrainment- and ablation-limited regimes. This project was jointly funded by the Geomorphology and Land-use Dynamics and Arctic Natural Sciences Programs.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.

大多数北极洪泛区都有永久冷冻的地下土壤或多年冻土，使沿海和河岸的土地保持完整和宜居。然而，永久冻结可以导致土地的普遍不稳定，并增强河岸侵蚀。这种侵蚀威胁着对国家繁荣和安全至关重要的关键基础设施，并导致了整个阿拉斯加社区的流离失所。该提案的主要目的是开发和测试多年冻土中河岸侵蚀的数学理论。该理论将使用加州技术地面动力学实验室的新型室内多年冻土河流实验进行测试，并通过与Huslia的本地阿拉斯加社区合作，通过AK Koyukuk River沿AK的Koyukuk River进行测量。这项工作有望填补我们对河流系统如何应对全球变暖的基本理解的空白。此外，它将为育空河流域河滨社区的气候变化适应计划做出贡献。下一代科学家将通过将社区参与以及基本和应用科学汇集在一起​​，以解决具有本地和全球影响的环境危机，以在综合危害评估中接受综合危害评估的培训。该提案的主要目的是开发和测试多年冻土中河岸侵蚀的热机械模型。除了寻求了解冷环境中银行侵蚀的基本机制外，该模型还将用于定量评估银行侵蚀率将如何响应气候变化。该模型将针对特殊设计的FLUME实验进行测试，以涵盖多种冻土河的特征范围，并测试与河流流速，河流水温和河岸沉积物谷物尺寸有关的假设。沿阿拉斯加Koyukuk河沿岸河岸的液压，机械和热性能的测量将用于评估夹带和消融限制度的模型。该项目是由地貌和土地利用动力和北极自然科学计划共同资助的。该奖项反映了NSF的法定使命，并使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估。