A comparison of the hydrological role of two reclaimed slopes of different age in the Athabasca Oil Sands Region, Alberta, Canada

Establishing hydrological connectivity in reconstructed landscapes, and understanding how this connectivity evolves over time, is critical for the development of effective water management strategies after oil sands extraction. In the current study, the dominant controls on the soil water regimes and runoff generation mechanisms on two contrasting reclaimed slopes (two and six years after reclamation) in the Athabasca Oil Sands Region are investigated. The most recently reclaimed slope demonstrated a hydrologic regime with limited soil water storage due to a low surface infiltration capacity that constrained percolation of rainfall. Accordingly, this slope generated a substantial amount of surface runoff controlled primarily by precipitation intensity. Conversely, the older slope had a greater surface infiltration capacity, more dynamic soil water regime and infrequent surface runoff. Topography controlled soil water distribution on the older slope more strongly than the newer slope due to more efficient water redistribution. This suggests that changes in the hydrophysical properties of reclamation materials following construction result in a shift in the hydrological role of reclaimed slopes at the watershed scale. Thus, over time, reclaimed slopes produce less overland flow and shift from water conveyors to water storage features in constructed watershed systems.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author