Integrating the effects of roots on the geoenvironmental behaviour of cover systems used to reclaim mine waste storage facilities

综合根系对用于回收矿山废物储存设施的覆盖系统的地质环境行为的影响

• 批准号: RGPIN-2020-06725
• 负责人: Guittonny, Marie
• 金额: $ 1.89万
• 依托单位: Université du Québec en Abitibi-Témiscamingue
• 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=741034
• 关键词: Integrating; effects; roots; geoenvironmental; behaviour

Engineered cover systems are used across Canada to mitigate environmental issues, such as acid mine drainage, associated to the storage of mine wastes. Acid mine drainage occurs when reactive mine wastes are in contact with atmospheric oxygen and water. Cover systems are designed to stop water and oxygen migration down to the reactive wastes they cover, thanks to targeted properties of their materials at construction. With time, cover systems are colonized by plants coming from adjacent ecosystems. Plants change the water content and movement in cover systems. More specifically, plant roots pump water and modify the physical, chemical and biological properties of cover materials. Thus, plants may affect the performance of cover systems to control the undesirable contact between water and/or oxygen with the reactive mine waste they cover. To predict the performance and design cover systems, engineers use numerical models of water budget, which can include vegetation's effects. But the prediction of the vegetation effects is often inaccurate. This mainly comes from the lack of values of vegetation parameters specific to the context of mine cover systems. In particular, root development is expected to be specific in cover systems, especially those constructed with several layers of differing materials (i.e. multilayered), but root studies in this context are scarce. Moreover, root dynamic growth and effect on the water movement in the cover system materials (i.e. effect on hydrogeotechnical properties) is not taken into account for the moment. The long-term objective of this research program is to improve and develop knowledge on the interactions between plants and engineered cover systems, with a focus on roots, to better predict the evolution of their performance with respect to ecosystem processes. This interdisciplinary research program will provide integrated root, hydrogeotechnical, and water budget data in the specific context of multilayered cover systems, with a focus on covers with capillary barrier effect used under humid climates. It will use field-scale and controlled laboratory monitoring, as well as numerical modeling. This work will decrease the uncertainty of vegetation parameter values required to design sustainable cover systems in the long-term. It will also document the evolution range of the hydrogeotechnical properties of cover system materials colonized by vegetation, especially mature trees. The research outcomes will constitute a knowledge basis for larger application to other waste containment technologies. A postdoc, 3 HQP and 3 UG interns will acquire interdisciplinary skills and will be able to design reclamation technologies responding to industrial, government, and communities' needs.

工程覆盖系统在加拿大各地使用，以减轻环境问题，如酸性矿山排水，与矿山废物的储存有关。酸性矿井水是矿山活性废物与大气中的氧气和水接触时产生的。覆盖系统的设计是为了阻止水和氧气迁移到它们覆盖的活性废物中，这要归功于它们的材料在建造时的目标特性。随着时间的推移，覆盖系统被来自相邻生态系统的植物占领。植物改变了覆盖系统中的水分含量和运动。更具体地说，植物根系泵水并改变覆盖物的物理、化学和生物特性。因此，植物可能会影响覆盖系统的性能，以控制水和/或氧气与它们覆盖的活性矿山废物之间的不良接触。为了预测覆盖系统的性能和设计，工程师使用水收支的数值模型，其中可以包括植被的影响。但是对植被效应的预测往往是不准确的。这主要是由于缺乏针对地雷覆盖系统背景的植被参数值。特别是，根的发育预计在覆盖系统中是特定的，特别是那些由几层不同材料构成的系统（即多层），但在这方面的根研究很少。此外，暂时没有考虑根系的动态生长和对覆盖体系材料中水分运动的影响（即对水文岩土力学性质的影响）。该研究计划的长期目标是提高和发展植物与工程覆盖系统之间相互作用的知识，重点是根，以便更好地预测其性能在生态系统过程中的演变。这个跨学科的研究项目将在多层覆盖系统的特定背景下提供综合的根系、水文岩土和水预算数据，重点是在潮湿气候下使用的具有毛细屏障效应的覆盖。它将使用现场规模和受控实验室监测，以及数值模拟。这项工作将减少设计长期可持续覆盖系统所需的植被参数值的不确定性。它还将记录植被，特别是成熟树木所覆盖的覆盖系统材料的水文岩土力学特性的演变范围。研究成果将为更广泛地应用于其他废物遏制技术奠定知识基础。1名博士后、3名HQP和3名UG实习生将获得跨学科技能，并能够设计满足工业、政府和社区需求的回收技术。