| dc.description.abstract | To accurately model soil temperatures on the Boreal Plain, factors that influence fine-grained
soils during the rapid cooling period must first be identified. The effects of air temperature, soil
moisture and snow depth were quantified at 0.1 and 0.5 m depths for 14 sites encompassing five
treatment types: three upland burned, three upland harvested, three upland conifer, three upland
deciduous and two wetland. In the absence of snow from September to October at the 0.1 m
depth, air temperature was identified as the most important parameter, explaining approximately
70% of the variation in soil temperature for upland and wetland sites. At the same depth in the
presence of snow from November to December, soil moisture was more important. At a deeper
soil depth (0.5 m), soil moisture was identified as the most important parameter regardless of
snow cover, explaining from 63 to 91% of the variation in soil temperatures for upland and
wetland sites. The presence of snow was a significant factor influencing soil temperatures, but
snow depth was not. Further, the soil temperature algorithms of SWAT were tested using one
site of each treatment type at 0.1, 0.5 and 1.0 m depths. The algorithms utilized by SWAT were
able to reproduce seasonal trends in soil temperatures adequately for the spring, summer and
autumn seasons, with only a slight increase in the lag coefficient parameter. During winter
months, the SWAT algorithms tended to predict soil temperatures that were consistently lower
than measured data. Further development to the SWAT soil temperature algorithms is required to
represent better the important insulating effect of snowpack. | en_US |
