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: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=740144
• 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.

地下水的化学含量在时间和空间上是不断变化的。风化、离子交换、盐溶和/或海水混合等过程往往会改变地下水质量，沿着其流向咸水末端的路径。很少有研究集中于通过考虑平衡常数、地下水流动状态和反应动力学(即反应路径模型)来确定盐化反应的连续阶段，很少关注陆相卤水的稀土元素特征。我的长期愿景是在UQAC建立一个实验实验室来研究水-岩石相互作用。在未来5年，我们将为未来的项目奠定基础，以实现这一长期目标。我们打算招聘2名博士(博士1和博士2)和1名硕士。(MSc1)学生开展即将到来的五年计划。我研究的短期目标是：1)探索裂缝和水/岩石相互作用对地下水盐化过程和地下水痕量和超痕量元素富集和/或亏损的作用；2)确定一套用于盐化过程端元化学的基准：(A)结晶基底的深水，(B)古生代石灰岩水，(C)水-粘土相互作用过程的水，(D)更新世冰川融水和(E)雨水；3)研究盐化过程的端元混合过程。为了实现第一个目标，博士1将专注于实验室实验和反应输运模型。Phd1将首先实施一个实验系统，研究裂缝和流体的地球化学变化所涉及的主要过程。利用观测、实验、模拟和理论方法，Phd1将提供高质量的机械和化学耦合过程数据，用于解释和预测流体化学的时间演化以及裂缝演化。为了实现第二个目标，PHD2将使用单变量和多变量统计分析技术调查数据收集。PHD2将确定基线化学特征，这可能构成在前寒武纪地盾范围内讨论水的来源和混合的任何新研究的基础。为了实现第三个目标，MSc1将利用尼奥贝克矿场的设施，更深入地了解咸水和近期陨石水之间的联系(混合/稀释过程)及其对地下水质量的影响。这三个研究项目是相互关联的，因此在第一年结束时，至少有两个学生将以跨学科的方法进行合作。UQAC认为，发展定量水文地球化学专门知识中心，补充已经建立的含水层水力学专门知识中心，将鼓励开展许多卓有成效的国内和国际合作，并有助于以科学为基础改进水资源管理。