| This thesis is an investigation of the use of poplar tree systems (PTS) as evapotranspiration barriers on two decommissioned landfills in southern Ontario. This study involved field-testing the Simultaneous Heat and Water (SHAW) model for its ability to estimate poplar transpiration, volumetric soil water content (&thetas;v), and soil temperature. The model was then used to estimate deep drainage at these landfills and to ascertain the influence of the PTS on the soil water balance. The SHAW model tended to underestimate poplar transpiration (MD ranged between 0.33 mm/day and 3.55 mm/day) and overestimate &thetas;v by up to 0.10 m3/m 3 (MD ranged between −0.09 m3/m3 and 0.06 m3/m3 on a mean annual basis). The model estimated soil temperature very well, particularly in the upper 1 m of the landfill cover, where MD ranged between −2.3°C and 1.6°C. The SHAW model simulated that deep drainage decreased appreciably with the presence of a PTS through increased plant interception and that, with a mature PTS scenario, deep drainage was almost completely eliminated year round.*; *This dissertation is compound (contains both a paper copy and a CD as part of the dissertation). The accompanying CD requires the following system requirements: Windows 95 or higher; Microsoft Office. |
