Assessing the impacts of climate change on the performance of engineered geobarriers in the Biotron

点击翻译按钮获取中文摘要

A number of studies have concluded that the Earth is getting warmer mostly because of increased greenhouse gas emissions resulting from anthropogenic activities, especially by industry. Various forecasts made by the International Panel on Climate Change suggest the Earth's temperature could rise by 1.8-4.6 °? by the end of this century. A warming climate in Canada could have negative impacts on water quantity and quality across the country. For example, climate models are predicting a 3-7oC rise in winter temperatures and a 4-8oC rise in summer temperatures in southwestern Ontario by the end of the century. The assessment of a waste containment system's vulnerability to climate change involves hazards identification and characterization of the system's exposure to an identified hazard, such as precipitation changes that could degrade components of the containment system (e.g.landfill covers). It is therefore important to assess the effects of precipitation changes on containment systems in order to develop adaptation strategies. The goal of the research program is to investigate the performance of selected engineered soil barriers used for waste containment (geobarriers) under a continuum of normal and climate change temperatures and precipitations in three geographical and climatic regions of the world: temperate climate (London, Ontario, Canada), Arctic climate (Murmansk, Northwest Russia), and humid, tropical savanna (Accra, Ghana). Over the long term, the program seeks to compare values of laboratory measured  hydromechanical, transport and sorption parameters for covers and liners under normal and climate climate conditions to those obtained on natural analogues. ***The study will involve sampling of uncontaminated natural clay and other soils from landfill areas in London, ON and Accra, Ghana, and iron oxides from the Kola Peninsula area of Northwest Russia for characterization and testing at Western University, Canada. The soils will be packed in large, instrumented columns (0.65 m3 or 22.5 ft3) to simulate landfill covers and liners and permeable reactive barriers subjected to sequential freeze-thaw and wet-dry cycles under normal and climate change temperatures and precipitations in a two-level climate chamber at The Biotron, Western University. The upper level can simulate ground air temperature, while the lower level can be set at the temperature in the ground. Both levels of the chamber can simulate a +40 °C to -40 °C temperature range. The effect of plant (grass) root growth on the soil covers will also be studied. The ultimate goal of the program is to develop a methodology for incorporating climate change impacts into the design of future waste containment systems or retrofit existing systems to endure climate change. The five-year program will train 13 highly qualified personnel: four doctoral, three master's and five undergraduate students and one postdoctoral fellow.**