Grant: Collaborative Research and Development Grants

The release of salts from reclamation landscapes into surrounding soils, groundwater, lakes and rivers is a major concern for the oil sands industry in Alberta. A fundamental problem is a lack of understanding of how cover systems in reclaimed landscapes function with respect to the water balance and salt releases. Hydrological processes in seasonally frozen, flat to gently sloping, semi-arid landscapes are already highly complex and difficult to quantify in models. In reclamation landscapes these problems are confounded by system properties and characteristics that evolve following initial placement, in particular due to establishment of vegetation and freeze-thaw cycle related weathering of the soils. This proposed applied research will develop new quantitative models to simulate the hydrological and salt transport processes for a set of extensively instrumented hillslopes within a reclamation landscape. The objective of the modelling is to test hypotheses about system functioning that have been developed over a number of years of study at this site, to try to fill in some of the unknown aspects of behaviour. Our focus is to develop an improved understanding of the physical processes, and to compare these to salt transport processes in natural landforms, specifically the salt rich Canadian prairies. We will explore the model sensitivity to physical properties (including topography, soils, geology and vegetation cover) which evolve over time, looking at whether changes in water balance and salt releases can be attributed to these physical changes in the system. We will explore the model sensitivity to climate variability, and how extremes (floods and droughts) might impact salt discharges. Finally, we will use modelling scenarios to explore the potential to engineer the landforms to retain salts in benign locations. In order to preserve the unique ecosystems and ecosystem services of the Canadian North, it is of direct interest to the Province of Alberta and Canada to understand and mitigate risks associated with overburden dumps. This project will help to better quantify some of the uncertainties with respect to the future performance of reclamation landforms created by the Canadian oil sands industry.