| Summary: | <p>The research presented in this thesis describes the application of the computer modeling
program Soil Cover 2000 as a tool for predicting the soil-atmosphere fluxes and
associated moisture movement in a variety of soil cover systems. The four systerns
examined for this thesis are used to reclaim a saline-sodic shale overburden deposit
located at the Syncrude Canada Limited mine site, 40 km North of Fort McMurray,
Alberta, Canada. The research represents the second phase of a cover instrumentation
and modeling research program.</p>
<p>Characterization of the soil cover materials and field responses was carried out during
phase one research conducted by Boese (2003) and Meiers (2002). The models were
made to simulate field conditions by using multi-modal soil-water characteristic curves
and hydraulic conductivity functions, and by estimating the growth of the plant species
found on the covers. Computed and measured field response patterns for the four cover
systems matched reasonably well for a five month period from May 19 to October 22,
2000. The models were then applied to predict the field measurements for the same
period during 2001. Only two adjustments needed to be made to the model parameters
in order to simulate the 2001 data; namely changing the dominant vegetation (and
related growth parameters) and; adjusting the saturated hydraulic conductivity to match
Meiers (2002) field measurements.</p>
<p>The calibrated model inputs were used to simulate five cover designs to test their
performance during extreme climate conditions. The main objective was to ascertain
whether a thinner cover system than the currently recommended cover thickness of 1 m
could be effective at the mine. The results indicate that the peat layer is required to
minimize the amount of runoff and to decrease the potential for saturated conditions·
forming at the base of the cover. For a peat-over-till cover system to work effectively,
the peat layer needs to be thicker than 30 cm to further reduce the potential for saturated
conditions forming at the base. However, thinning the till layer is acceptable since the
results show that a thinner till layer has little impact on the performance of the cover.
The overall cover thickness needs to be greater than 60 cm to improve plant survival.</p>
<p>***Addendum on last page***</p>
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