Numerical modelling of integrated hydrogeological systems in complex porous and fractured media

复杂多孔和裂缝介质中综合水文地质系统的数值模拟

• 批准号: RGPIN-2014-05873
• 负责人: Molson, John
• 金额: $ 2.7万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611895
• 关键词: Numerical; modelling; integrated; hydrogeological; systems

Canada has some of the world's most abundant groundwater resources which are critical for drinking water, agricultural and industrial use, and for maintaining ecosystems and stream flow. These resources are being threatened by over-exploitation, contamination and climate change. Some of the most complex groundwater systems are found within fractured porous media which are challenging to characterize, remediate, and protect. This Discovery Grant Proposal "Numerical modelling of integrated hydrogeological systems in complex porous and fractured media" outlines a research plan for developing and applying new computational modelling approaches to test conceptual models, to better protect and manage groundwater resources, and to improve our ability to remediate contaminated sites and prevent future impacts. The proposal has been developed in part within the context of the Researcher's Tier II Canada Research Chair in Quantitative Hydrogeology of Fractured Porous Media. The proposal contains three primary research themes involving numerical modelling of fractured systems: 1. Development of numerical methods for protecting groundwater resources in fractured rock aquifers, 2. Applying numerical models to optimize remediation of contaminated fractured aquifers, and 3. Understanding the risks from fractured hydrogeological systems under stressed conditions. Developing quantitative numerical tools for ensuring sustainable use of limited groundwater resources is the underlying objective encompassing all themes. Theme 1 of the proposal will focus on developing new numerical tools and modelling approaches for protecting groundwater in fractured rock aquifers which are becoming more commonly used for urban and rural water supply. New computational techniques for identifying source water provenance for municipal water supply wells in fractured rock, and for predicting groundwater age and life expectancy as a measure of aquifer and well vulnerability, respectively, will be fully developed for discretely-fractured porous media in three dimensions. In aquifers which are already contaminated, more efficient and cost-effective remediation methods are needed. Under Theme 2, a robust 3D numerical flow and transport model will be developed for simulating 'treatment-train' persulfate-ISCO (in-situ chemical oxidation) remediation of groundwater contaminated by petroleum hydrocarbons. The approach includes sulfate-enhanced in-situ bioremediation (IBR), coupled to reactions with the natural background geochemistry. The model will be developed for both porous and discretely-fractured porous media, and will be tested at monitored field sites under various hydrogeologic conditions. Optimal design parameters (including injection concentrations, flow rates, and treatment sequence timing), uncertainty, and effects of heterogeneity and background geochemistry will be investigated. Theme 3 addresses environmental impacts of shale gas development on groundwater resources, focusing on simulating potential disturbances to deep regional flow systems in fractured rock caused by hydraulic fracturing, and assessing the leakage risks of methane gas and formation brines into shallow freshwater aquifers. These environments challenge current models and require innovative numerical strategies to fully understand. The simulation results will be used to help design groundwater monitoring strategies for early detection of impacts on drinking water resources. The proposal will lead to direct HQP training of 2 MSc and 2 PhD students.

加拿大拥有一些世界上最丰富的地下水资源，这些资源对饮用水、农业和工业用途以及维持生态系统和溪流至关重要。这些资源正受到过度开采、污染和气候变化的威胁。一些最复杂的地下水系统存在于裂隙多孔介质中，这对表征、修复和保护具有挑战性。 探索基金的这项提案“复杂多孔和裂隙介质中综合水文地质系统的数值模拟”概述了一项研究计划，旨在开发和应用新的计算模拟方法来测试概念模型，更好地保护和管理地下水资源，并提高我们修复受污染场地和防止未来影响的能力。这项提议部分是在研究人员关于裂隙多孔介质定量水文地质学的加拿大第II级研究教席的背景下提出的。 该提案包含三个主要研究主题，涉及裂缝系统的数值模拟： 1.裂隙岩含水层地下水资源保护数值方法的发展， 2.应用数值模型优化受污染裂隙含水层的修复，以及 3.了解破裂水文地质系统在压力条件下的风险。 开发量化的数字工具以确保可持续利用有限的地下水资源是涵盖所有主题的基本目标。 该提案的主题1将侧重于开发新的数值工具和建模方法，以保护裂隙岩石含水层中的地下水，这些含水层正越来越普遍地用于城市和农村供水。对于三维离散裂隙多孔介质，将充分开发新的计算技术，以确定裂隙岩石中市政供水井的水源来源，并预测地下水年龄和预期寿命，分别作为衡量含水层和井脆弱性的指标。 在已经受到污染的含水层，需要更有效和更具成本效益的补救方法。在主题2下，将开发一个强大的三维流动和传输数值模型，用于模拟过硫酸盐-原位化学氧化(ISCO)修复受石油碳氢化合物污染的地下水。该方法包括硫酸盐强化的原位生物修复(IBR)，以及与自然背景地球化学的反应。该模型将开发用于多孔和离散裂隙的多孔介质，并将在不同水文地质条件下的监测现场进行测试。将调查最佳设计参数(包括注入浓度、流速和处理顺序时间)、不确定性以及非均质性和背景地球化学的影响。 主题3涉及页岩气开发对地下水资源的环境影响，重点是模拟水力压裂对裂隙岩石中深层区域流动系统的潜在扰动，并评估甲烷气体和地层卤水进入浅水含水层的泄漏风险。这些环境挑战了当前的模型，需要创新的数值策略才能完全理解。模拟结果将被用来帮助设计地下水监测战略，以便及早发现对饮用水资源的影响。 该提案将直接对2名硕士和2名博士生进行HQP培训。