Improving crystalline bedrock aquifer conceptual models using novel discrete fracture network methods

使用新颖的离散裂缝网络方法改进结晶基岩含水层概念模型

• 批准号: RGPIN-2014-03973
• 负责人: Levison, Jana
• 金额: $ 1.82万
• 依托单位: University of Guelph
• 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=610754
• 关键词: Improving; crystalline; bedrock; aquifer; conceptual

Fractured bedrock aquifers are widely used for domestic and municipal water supply in Canada and internationally. Understanding fracturing in bedrock formations is also critical to assessing deep geological repositories and petroleum exploitation. Where only thin (or no) glacial deposits cover rock formations, shallow crystalline bedrock aquifers can be vulnerable to contamination from human activities. Fractures are primary conduits for contaminant transport. Crystalline fractured bedrock aquifers underlie much of central and eastern Canada (e.g., the Canadian Shield) and eastern, north-central and northwestern United States. These aquifers have low rock matrix porosity and thus low capacity for contaminant diffusion. Water and contaminants travel predominantly through rock fractures at often high groundwater velocities and thus there is potential for rapid transport rates. In order to help protect these aquifers for water supply, robust methods are required to improve the hydraulic characterization and understanding of crystalline aquifers. The systematic Discrete Fracture Network (DFN) Approach (Parker, 2007) has been widely used by researchers in the G360 Centre for Applied Groundwater Research group to characterize sedimentary bedrock aquifers for flow and contaminant transport applications. The objective of the proposed research program is to apply several novel pillars of this DFN Approach in order to: 1) use the methods for the first time in the crystalline bedrock of the Canadian Shield as opposed to sedimentary bedrock (e.g., dolostone); and 2) compare new results to previous hydraulic characterization research conducted using different methods (i.e., straddle packer slug tests, pumping tests and down hole video-logging) and to contaminant transport studies conducted at the field sites. The results will be applied to improve conceptual models for flow and contaminant transport for shallow fractured crystalline bedrock aquifers. This research will include specifically: 1) depth-discrete measurements of permeability and flow using specialized flexible and impermeable borehole liners (FLUTe™); 2) high resolution temperature profiling for identifying hydraulically active fractures; 3) novel cross-hole tests using pressure, heat and dye as tracers coupled with the liners, interpreted via numerical modeling; and 4) post hydraulic characterization water quality (nitrate and turbidity) monitoring using in situ probes and liners. This research economizes by using existing extensive well infrastructure drilled into the Canadian Shield at the Tay River Field Site (Levison et al., 2012) and Kennedy Field Station (Elmhirst and Novakowski, 2012). About 20% of the land surface comprises crystalline shield rock (Gustafson and Krásný, 1994). A thorough understanding, using multiple lines of evidence, of fracture parameters including apertures, transmissivity, spacing, and connectivity are required for all flow, contaminant transport and remediation efforts, with applications in water resources engineering, hydrogeology and natural resource exploitation. Novel methods of the G360 DFN Approach will be applied in a research environment with the opportunity to compare results to previous characterization efforts and field experiments. Also, a unique in situ nitrate probe and fluorometer will be tested with lined boreholes. This research will contribute to important applications for water supply and contaminant migration, including source protection, and provide consultants and researchers effective, cost efficient tools for rapidly characterizing crystalline aquifers. The research will be carried out by doctoral, Master’s and undergraduate students who will gain valuable training applicable to work in industry or continued research.

裂缝是在加拿大广泛用于国内供水的，而国际则是批判性的耐甲质供应。盾牌和北方北部和北部的北部和北部岩石孔隙率低。 G360中心Forndwat Er研究小组中的研究人员广泛使用了系统的离散断裂网络（DFN）方法（Parker，2007年）来表征Rogram的表征，是将方法的分层应用于OPP晶体底石的结晶基岩。对沉积基岩（例如，多洛酮）和2）进行了与先前使用不同方法进行的水合物表征研究（即，跨封装测试，泵送测试和下孔视频量）IES结果将用于改善概念的流量和污染物的运输，用于浅层晶体基岩含水层。否）否）否）否）使用压力，热和染料作为示踪剂与衬里的vel孔测试，以及4）使用原位探针和衬里的水力表征水质（硝酸盐和涡轮） Tay River Field遗址（Levison等，2012）和肯尼迪野外车站（Elmhirst和Novakowski，2012年）的加拿大盾牌。 大约有20％的土地岩石（Gustafson和Krásný，1994年）将在以前的特征和田地上进行反对的环境，并用衬里的井眼测试唯一的硝酸盐探针和荧光计。由博士，硕士和地下地下学生进行的，这些学生将获得适用于行业或持续研究的有价值的培训。