Permafrost hydrogeology

多年冻土水文地质学

• 批准号: RGPIN-2017-05298
• 负责人: Clark, Ian
• 金额: $ 2.33万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=711602
• 关键词: Permafrost; hydrogeology

Increasing temperatures in the Arctic over the past decades has been accompanied by an increase in sub-permafrost and intra-permafrost groundwater discharge to rivers. Hydrometric data from permafrost drainage basins show strong interannual variability in baseflow discharge, although with a long term trend towards increased groundwater discharge. This increased flow can affect seasonal discharge in rivers, the timing and severity of the spring freshet and may also exacerbate the impact of seasonal icing (aufeis) formation on communities and infrastructure. This program will take full advantage of Canada's only accelerator mass spectrometer facility that we recently established at the University of Ottawa, with capabilities for very low level and compound-specific radiocarbon plus associated facilities for noble gas isotopes analysis. The objective of this research program over the next five years is to determine the mechanisms of groundwater recharge and quantify circulation through permafrost watersheds, the impacts of climate variability, and how contaminants are transported through components of these flow systems. Spectral analysis of discharge data shows strong correlations with climate phenomena observed for the western Canadian Arctic, including the solar cycles and El Nio. This collaborative research will integrate spectral and statistical analysis of historical hydrological and climatological data sets with field investigations and laboratory analysis of stable and radioisotopes and noble gases , to build a comprehensive model of the seasonal timing, mechanisms and climate controls on groundwater circulation. Collaboration with northern groups (Yukon College, Gwitch'in Land and Water Board; Yukon Water Survey, Environment Yukon) will continue to provide access, field guides through backcountry terrain, sampling assistance for project HQP and northern knowledge. Sampling to characterize groundwater baseflow during the pre-freshet period and the spring freshet through to freeze-up. Analysis includes isotopes and the carbon system (13C and 14C, DIC, CH4, DOC, acetate and other fractions). This program will contribute new research at contaminated sites to help calculate rates of biodegradation of contaminants in soils. We will measure rates of biodegradation and organic contaminant migration in development-impacted watersheds. HQP in this work gain extensive northern research experience and are exposed to the latest analytical methods in our new Advanced Research Complex (ARC) including radiocarbon by AMS and noble gases. This research program is one of very few considering the groundwater component of permafrost hydrology, and the fate of organic contaminants in these systems. This is of particular relevance to a region experiencing accelerated development at a time of shifting climate regimes.

在过去几十年里，北极地区气温上升的同时，向河流排放的冻土层以下和冻土层内地下水也有所增加。来自多年冻土流域的水文数据显示，基流流量具有很强的年际变异性，但长期趋势是地下水流量增加。这种增加的流量可能会影响河流的季节性流量、春季淡水的时间和严重程度，还可能加剧季节性结冰(Aufeis)对社区和基础设施的影响。该计划将充分利用我们最近在渥太华大学建立的加拿大唯一的加速器质谱仪设施，具有极低水平和化合物特定放射性碳的能力，以及用于惰性气体同位素分析的相关设施。这项研究计划在未来五年的目标是确定地下水补给的机制，量化通过永久冻土流域的循环，气候变化的影响，以及污染物如何通过这些流动系统的组成部分传输。 对放电数据的频谱分析表明，这与在加拿大西部北极观测到的气候现象有很强的相关性，包括太阳活动周期和厄尔尼诺现象。这项合作研究将把历史水文和气候数据集的光谱分析和统计分析与稳定、放射性同位素和惰性气体的现场调查和实验室分析相结合，以建立一个关于地下水循环的季节时间、机制和气候控制的综合模型。 与北方团体(育空学院、Gwitch‘in土地和水委员会；育空水资源调查、环境育空)合作，将继续提供准入、野外实地指导、HQP项目抽样援助和北方知识。取样，以确定地下水在前淡水时期和春季淡水至冻结期间的基本流量。分析包括同位素和碳系(13C和14C、DIC、CH4、DOC、醋酸盐和其他组分)。该计划将在受污染的地点进行新的研究，以帮助计算土壤中污染物的生物降解率。我们将测量受发展影响的流域的生物降解率和有机污染物迁移率。 在这项工作中，HQP获得了广泛的北方研究经验，并在我们新的高级研究综合体(ARC)中接触到最新的分析方法，包括AMS的放射性碳和惰性气体。这个研究项目是为数不多的考虑多年冻土水文中的地下水成分，以及有机污染物在这些系统中的去向的研究项目之一。这对于一个在气候制度转变时期正在经历加速发展的区域特别重要。