The biogeochemical response of High Arctic surface waters to changing permafrost and hydrology

高北极地表水对永久冻土和水文变化的生物地球化学反应

• 批准号: RGPIN-2014-04124
• 负责人: Lafreniere, Melissa
• 金额: $ 3.93万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=656350
• 关键词: biogeochemical; response; Arctic; surface; waters

The proposed research investigates the control that spatial and temporal variations in hydrologic processes (such as precipitation and soil moisture) and permafrost disturbances (such as active layer detachments, ALDs) exert on active layer biogeochemical processes and on downstream river water quality, especially nutrients and organic matter, in High Arctic watersheds. This integrated research program will provide baseline knowledge required to develop means of predicting the water quality response of High Arctic rivers to projected climate change. **My research is necessitated by the potential for climate change in permafrost regions to have widespread impacts on hydrology and permafrost stability, which combined will significantly impact terrestrial ecosystem function, river water quality and downstream aquatic ecosystems. Recent studies show that warming, permafrost disturbances and changes in precipitation regimes can lead to increases in nutrients and dissolved organic matter (DOM) concentrations in arctic rivers. These increases occur primarily in the late season when rainfall and concentrated subsurface water sources contribute to runoff. However, there are still conflicting accounts of the relationship between climate and the riverine transport of solutes, inorganic nitrogen (N) and DOM. These conflicts are due in part to differences in the nature of the permafrost and geologic substrate, as well as a general lack of understanding of the spatial and temporal variability in the biogeochemical processes controlling solute production and storage in the watershed, and the hydrologic processes controlling solute mobilization and export in runoff. This research addresses this knowledge gap by combining catchment scale studies of (1) the sources and quality of subsurface water flow, with small-scale field and lab experiments investigating the control of (2) the physical and geomorphological characteristics of soils, and (3) rainfall on biogeochemical processes in the active layer. **It is the integrated nature of this research, and the explicit linking of investigations of the watershed scale geomorphic and seasonal hydrological controls on solute mobilization, with site-specific studies examining the key physical controls on subsurface water flow and biogeochemical controls on nutrient and DOM cycling in the active layer that makes this research novel and highly relevant. This work will facilitate moving from site-specific knowledge, to a catchment scale understanding of the impact of changing climate on water quality in permafrost watersheds. The research will generate quantitative data that is critical to informing policy and managing High Arctic water resources to ensure healthy ecosystems and protect water security in Arctic communities that are already subject to perceptible regional climate change.**Highly qualified personnel (HQP) will be trained at the Cape Bounty Arctic Watershed Observatory (CBAWO), a collaborative and integrated watershed research station that is unique in the Canadian Arctic. The proposed research program will provide eight HQP with a project management experience, and a breadth of field and analytical skills. Students exit the program with the advanced knowledge required to assess the vulnerability of artic watersheds and ecosystems to climate change and human impacts. The careers secured by graduates of my research program demonstrate that the knowledge and skill sets HQP acquire are highly valued by private industry and government. HQP will be poised to contribute to decision-making, and the development of practices that will improve our ability to manage Arctic environments and water resources in a changing climate, and thus benefit the health and economic well being of all Canadians.

拟议的研究调查的控制，水文过程（如降水和土壤水分）和冻土扰动（如活动层determination，ALDs）的空间和时间变化施加在活动层地球化学过程和下游河流水质，特别是营养物质和有机物质，在高北极流域。这项综合研究计划将提供所需的基线知识，以开发预测高北极河流水质对预计气候变化的响应的方法。** 我的研究是必要的气候变化在永久冻土地区的潜力，对水文和永久冻土稳定性产生广泛的影响，这将大大影响陆地生态系统功能，河流水质和下游水生生态系统。最近的研究表明，变暖，永久冻土扰动和降水状况的变化可能会导致北极河流中营养物质和溶解有机物（DOM）浓度的增加。这些增加主要发生在季节后期，此时降雨和集中的地下水源有助于径流。 然而，气候与溶质、无机氮（N）和DOM的河流输送之间的关系仍然存在相互矛盾的说法。这些冲突部分是由于永久冻土和地质基底的性质的差异，以及普遍缺乏了解的空间和时间的变化在流域控制溶质的生产和储存的地球化学过程，控制溶质的动员和出口径流的水文过程。本研究通过将以下方面的流域尺度研究与小规模实地和实验室实验相结合来解决这一知识差距：（1）地下水流的来源和质量，（2）土壤的物理和地貌特征，（3）降雨对活动层地球化学过程的控制。** 这是本研究的综合性质，明确连接的流域尺度地貌和季节性水文控制溶质动员的调查，与特定地点的研究，检查关键的物理控制地下水流量和生态地球化学控制的营养和DOM循环的活动层，使这项研究的新颖性和高度相关。 这项工作将有助于从特定地点的知识，到一个流域尺度的了解气候变化对水质的影响，在永久冻土流域。该研究将产生定量数据，这些数据对于制定政策和管理北极水资源至关重要，以确保健康的生态系统并保护已经受到可感知的区域气候变化影响的北极社区的水安全。高素质人员将在邦蒂角北极流域观测站接受培训，该观测站是加拿大北极地区独一无二的合作和综合流域研究站。拟议的研究计划将为八名HQP提供项目管理经验，以及广泛的领域和分析技能。学生退出程序与先进的知识需要评估北极流域和生态系统对气候变化和人类影响的脆弱性。我的研究项目的毕业生所获得的职业证明，HQP获得的知识和技能受到私营企业和政府的高度重视。 HQP将随时准备为决策做出贡献，并制定实践，以提高我们在气候变化中管理北极环境和水资源的能力，从而使所有加拿大人的健康和经济福祉受益。