Development of a quantitative framework to better understand the natural salinization processes of continental groundwater.

开发定量框架以更好地了解大陆地下水的自然盐化过程。

• 批准号: RGPIN-2020-04721
• 负责人: Walter, Julien
• 金额: $ 2.19万
• 依托单位: Université du Québec à Chicoutimi
• 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=716887
• 关键词: Development; quantitative; framework; better; understand

The chemical content of groundwater is continuously modified through time and space. Weathering, ion exchange, salt dissolution and/or seawater mixing are among the processes that tend to modify groundwater quality along its flow path, toward a saline endmember. Few studies have focused on defining the successive stages of salinization reactions by considering equilibrium constants, groundwater flow regimes and reaction kinetics (i.e., reaction path modelling), with little attention paid to the rare earth element (REE) signature of continental brines. My long-term vision is to establish an experimental laboratory at UQAC to study water-rock interactions. Over the next 5 years, we will lay the foundation for future projects to achieve this long-term goal. We intend to hire 2 PhD (PhD1 and PhD2) and 1 M.Sc. (MSc1) students to carry out the coming 5-year project. The short-term objectives of my research are: 1) To explore the role of fractures and water/rock interaction on groundwater salinization processes and groundwater enrichment and/or depletion in trace and ultra-trace elements; 2) To determine a set of benchmarks for the chemistry of endmembers of salinization processes: (a) deep waters of the crystalline basement, (b) Paleozoic limestone waters, (c) waters originating from water-clay interaction processes, (d) Pleistocene glacial meltwater, and (e) rainwater; 3) To investigate endmember mixing processes. To achieve the first objective, PhD1 will focus on lab experiments and reactive transport modeling. PhD1 will first implement an experimental system to study the main processes involved in the geochemical alteration of fractures and fluids. Using observational, experimental, modelling and theoretical approaches, PhD1 will provide high-quality data on coupled mechanical and chemical processes for the interpretation and prediction of temporal evolution of fluids chemistry, as well as fracture evolution. To achieve the second objective, PhD2 will investigate a collection of data using univariate and multivariate statistical analysis techniques. PhD2 will determine baseline chemical signatures which may form the basis of any new studies in the context of the Precambrian Shield to discuss the origin and mixtures of water. To achieve the third objective, MSc1 will provide a deeper understanding of the connection between salt water and recent meteorite water (mixing/dilution processes) and its impact on groundwater quality, using Mine Niobec facilities. The 3 research projects are interrelated such that by the end of the first year, at least two students will be collaborating in an interdisciplinary approach. For UQAC, the development of a center of expertise in quantitative hydrogeochemistry in complement to the already well-established center of expertise in aquifer hydraulics will encourage many very fruitful national and international collaborations and contribute to the evolution of science-based improvements in water resource management.

地下水的化学成分在时间和空间上不断变化。风化、离子交换、盐溶解和/或海水混合是倾向于改变地下水水质的过程，这些过程沿着地下水流向含盐端元的流动路径沿着进行。很少有研究集中在通过考虑平衡常数、地下水流动状况和反应动力学（即，反应路径模型），很少注意到大陆卤水的稀土元素（REE）特征。我的长期愿景是在UQAC建立一个实验室，研究水岩相互作用。在接下来的5年里，我们将为未来的项目奠定基础，以实现这一长期目标。我们打算聘请2名博士（PhD 1和PhD 2）和1名硕士（MSc 1）学生来执行未来5年的项目。本研究的短期目标是：1）探索断裂和水/岩相互作用对地下水盐渍化过程和地下水中微量和超微量元素富集和/或贫化的作用; 2）确定一套盐渍化过程端元化学的基准：（a）结晶基底的深层沃茨，（B）古生代石灰岩沃茨，（c）源于水-粘土相互作用过程的沃茨，（d）更新世冰川融水，和（e）雨水; 3）研究端元混合过程。为了实现第一个目标，博士1将专注于实验室实验和反应性运输建模。PhD 1将首先实施一个实验系统，以研究断裂和流体的地球化学蚀变中涉及的主要过程。使用观测，实验，建模和理论方法，博士1将提供高质量的数据耦合的机械和化学过程的解释和预测流体化学的时间演变，以及裂缝演化。为了实现第二个目标，博士2将调查使用单变量和多变量统计分析技术的数据集合。PhD 2将确定基线化学特征，这些特征可能构成前寒武纪地盾背景下任何新研究的基础，以讨论水的起源和混合物。为了实现第三个目标，MSC 1将提供盐水和最近的陨石水（混合/稀释过程）之间的联系及其对地下水质量的影响，使用矿山Niobec设施更深入的了解。这三个研究项目是相互关联的，这样到第一年年底，至少有两名学生将在跨学科的方法合作。对于UQAC，定量水文地球化学专业知识中心的发展，以补充已经建立的含水层水力学专业知识中心，将鼓励许多非常富有成效的国家和国际合作，并有助于水资源管理的科学改进。