A multi-tool, multi-method approach for improved qualitative and quantitative characterization of hydraulic groundwater relationships and resources

一种多工具、多方法的方法，用于改进水力地下水关系和资源的定性和定量表征

• 批准号: RGPIN-2019-07117
• 负责人: Chesnaux, Romain
• 金额: $ 2.26万
• 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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683733
• 关键词: multi; tool; method; approach; improved

Pumping wells are usually installed in a well-identified aquifer, either granular (composed of sand and gravel) or fractured rock. It is assumed that the groundwater extracted from the well comes from the aquifer in which the well is installed. However, there is a particular case which has not yet been well documented in the literature, nor thoroughly investigated so far: that of pumping wells which are installed either in deposit or in fractured rock, but in both instances, close to the interface between these two types of aquifers. Within a regional geological framework where granular layers usually overlay the fractured bedrock, pumping wells may happen to be installed either in the lower part of the deposit just above the bedrock, or in the upper part of the bedrock, just below the deposit. In both of these configurations, one may suspect that the water produced by the pumping well could be composed of a mix of two different groundwaters: one coming from the deposit and the other coming from the bedrock. This situation would arise if hydraulic connections exist between the two types of aquifers. Such connections may be naturally preexisting, where discontinuities of the fractured rock would naturally intersect with the deposit. Or they may be artificially induced, in the case where drilling operations through the rock have created a hydraulic connection between the aquifers (preferential pathways along the bottom part of the casing, penetrating the upper part of the fractured rock). In both configurations, the pumping wells could be qualified as “mixt wells” because they collect waters originating from both the granular aquifer and the fractured-rock aquifer. The aim of this proposed research is to set up a methodology allowing to characterize the hydraulic connections between the two types of aquifers. This characterization would allow us to quantify the groundwater exchanges between the two types of aquifers close to the wells and at local and regional scales, and to help to understand the origin of groundwater supplied by wells. These aspects are of crucial importance when appropriately managing groundwater resources. More knowledge will be gained about origins of possible contaminations. This proposed research will also lead to the establishment of new tools for assessing the vulnerability of aquifers and ensuring a better protection of the resource. The proposed approach to perform this research is holistic in nature and combines the following: establishing the theoretical bases of the investigated issue, performing in situ field tests, modeling and numerical tests.

抽水井通常安装在已明确的含水层中，无论是颗粒状（由沙子和砾石组成）还是裂隙岩石。假设从井中提取的地下水来自井所在的含水层。文献中尚未详细记载，也没有进行彻底调查的特殊情况：抽水井安装在矿床或裂隙岩石中，但在这两种情况下，都靠近这两种类型之间的界面在颗粒层通常覆盖裂隙基岩的区域地质框架内，抽水井可能恰好安装在基岩上方的沉积物下部，或沉积物下方的基岩上部。在这两种配置中，人们可能怀疑抽水井产生的水可能由两种不同地下水的混合物组成：一种来自沉积物，另一种来自基岩，如果两者之间存在水力连接，就会出现这种情况。两种类型的含水层可能是自然存在的，其中裂隙岩石的不连续性会自然地与沉积物相交，或者在穿过岩石的钻探作业在含水层之间形成水力连接的情况下，它们可能是人为引起的。 （沿着套管底部的优先通道，穿透裂隙岩石的上部）在这两种配置中，抽水井都可以被称为“混合井”，因为它们收集水。这项研究的目的是建立一种方法来描述这两种类型的含水层之间的水力联系，从而量化这两种含水层之间的地下水交换。在适当管理地下水资源时，这些方面至关重要。这项拟议的研究还将导致建立新的工具来评估含水层的脆弱性并确保更好地保护资源。拟议的研究方法本质上是整体性的，并结合了以下内容：所研究问题的理论基础，进行现场现场测试、建模和数值测试。