Burns Bog covers approximately 3,000 hectares between the Fraser River and Boundary Bay in Delta, BC. An ecologically unique ecosystem, its hydrology and ecology have been widely disturbed. Hydrology strongly shapes the character and distribution of vegetation and Sphagnum growth. This study investigated measures of hydrology, including water table residence times and cumulative moisture deficits, to quantify intuitive relationships between moisture stress and ecological zones. Regression analysis of quantitative field observations reveal statistically significant relationships between cumulative moisture deficits and several key bog plant species and Lodgepole pine (Pinus contorta) diameter at breast height, signifying that these relationships can be used to predict the potential for vegetation recovery. Sphagnum height measurements reveal the unexpected observation that most growth occurs during the cool moist winter and early spring. This study contributes to the hydrological management of Burns Bog and will help to guide the location and mechanisms of restoration efforts.

Cold in-place recycling with expanded asphalt mix (CIREAM) has become an accepted road rehabilitation technique in Ontario and other parts of the world given its advantages over regular cold in-place recycling (CIR) and other methods. Although CIREAM offers early strength advantages and extended paving periods among other benefits, late season CIREAM can be burdened by distresses such as ravelling, potholing and other moisture-induced damage. Limited information on the behaviour and failure mechanisms of CIREAM has also hindered its utilization in spite of the numerous benefits. This research investigated effects of additives on foam properties of roofing asphalt flux (RAF) binder in order to evaluate the suitability of the binder for CIREAM. The study also investigated how mixture variables and test protocols affect performance properties that relate to early strength and moisture resistance of CIREAM versus CIR. Indirect tensile strength testing with moisture conditioning was used to assess the effects of asphalt cement type (80, 300 pen grades and polymer modified asphalt), conditioning time, and additives such as Portland cement, foam stabilizers, polymers and fibers. Uniaxial cyclic compression with partial confinement was used to assess effect of additives on deformation resistance of recycled mixes. Although a siloxane-based stabilizer significantly improved the stability of RAF foam, the binder may not be suitable for CIREAM due to its limited expansion. The optimum binder content was found to be around 2 percent, which is significantly higher than the minimum 1 percent currently used in Ontario. Both Portland cement and the siloxane additive exerted significant positive effects on strength behaviour and moisture resistance of the recycled mixes. In regular CIR mixes, 2 percent binder content gave desirable early strength and strain performance compared to 1 percent. Application of controlled amounts of additives (e.g. Portland cement, foam stabilizers) and case-by-case evaluation can improve the performance properties of CIREAM and address the associated problems. The entire research effort described in this thesis was designed to provide advice on potential improvements in the CIREAM process as it is currently carried out in Ontario, and also help in developing quality control standards in CIREAM and other cold mix processes. / Thesis (Master, Chemistry) -- Queen's University, 2014-04-16 08:42:24.313

Three studies were undertaken from 2006 to 2007 to examine litter (dead plant material) in southwestern Manitoba pastures. First, the relationship between litter and soil microclimate was tested across five pasture sites. The amount of litter biomass was not strongly related to soil moisture, though near-surface soil temperatures were reduced when litter was present. Second, the effect of four simulated grazing strategies on the litter layer was measured in six pastures. It was found that after three years of simulated grazing, litter was present in largest quantities in the least-frequently grazed treatments. Finally, a field survey was conducted assessing the quantity of litter present in native pastures across Manitoba. Litter was quite variable and averaged 1902 kg/ha over two years. This research confirmed the value of litter as an indicator of sustainable pasture management, though it remains unclear whether litter is important to pastures from the perspective of soil microclimate.

To assess the accuracy of the second-generation Prairie Agrometeorological Model (PAM2nd) as an agrometeorological model for spring wheat on the Canadian Prairies, a study was conducted to validate the model using field measurements. Results from model validation indicated soil moisture was being overestimated at most sites during the second half of the growing season, while soil moisture was underestimated during periods that experienced consecutive days of rainfall. Modifications to the model were implemented to improve the model's ability to simulate soil moisture. Evapotranspiration estimates from PAM2nd and the FAO56 Penmen-Monteith method were compared to water balance methods. Both models produced estimates that fell within the range of water balance ET measurement error. The similarity in performance of both models to estimate ET compared to the water balance ET means the adoption of either model could be justified. However, PAM2nd would be more appropriate because it requires fewer, more commonly measured, surface weather parameters.

No description available.

Note: / ln May 1962 the McGill University Savanna Research Project wasestablished and has been conducted since that date in the Department ofGeography p McGill University and in the savannas of the Rupununi Di strict pBritish Guiana and the Territorio do Rio Brancop Brazi!.It is generally recognised that although a very wide range of theoryhas been propounded to explain the nature and origin of savannas p no onehas yet brought forward a single convincing viewpoint which has met withuniversal acceptance. One reason for this is that the majority of theoriesextant are based upon inadequate fie ld data with almost a total lack ofexperimental evidence. The McGill Univers ity Sa vanna Research Projectwas set up for the purpose of initiating an experimental and observati onalfield programme which it was hoped would shed light upon the ecologicalrelations of the savanna p and would ultimately enable an explanation to bemade of the nature and distribution of the savanna vegetation of the region .

Effective management of saline soils requires rapid, reliable methods of monitoring both soil water content (theta) and salt concentration, the latter measured in terms of electrical conductivity (sigma). This thesis examines estimation of theta, and bulk soil sigma (sigmaa) and soil water sigma (sigmaw), using time domain reflectometry (TDR). Calibration experiments were conducted in soil columns and in a vineyard that were irrigated with saline water. Within a theta range of 0.025--0.490 m3/m3, the correlation between TDR theta (thetaTDR) and gravimetrically determined theta (theta g) was high (r2 = 0.979 in soil columns, r2 = 0.836 in the field). The error of estimate of thetaTDR was 0.020 m3/m3 or less. Field thetaTDR estimates were sensitive to high salinity (sigmaw > 10 dS/m). Using a dual pathway parallel conductance (DPPC) model, sigma a was derived from sigmaw of saturated paste extracts and theta g. The correlation of TDR sigmaa to DPPC sigmaa was good in the laboratory (r2 = 0.915), and moderate in the field (r2 = 0.791), indicating a functional relationship between sigmaw and theta and TDR sigmaa. Models, to estimate sigmaw, were built by regression between paste extract sigma w and TDR sigmaa and thetaTDR. In a sigma w range of 3.0--23.4 dS/m in the columns, error of estimate of sigma w was small at 1.50 dS/m (+/-12.4% relative error range). In a sigma w range of 2.2--25.2 dS/m in the field, error of estimate of sigma w was 3.37 dS/m (+/-37% relative error range), which was significantly higher than the acceptable error range of +/-10%. ANOVA tests indicated that both TDR sigmaa and sigmaw·theta changed significantly with respect to the same sources of variance. Error in field estimates of sigmaw was associated with effects of salinity on thetaTDR and variability of soil conditions, particularly with respect to depth and time of sampling.

No description available.

Time domain reflectometry (TDR) is becoming a widely used method to determine volumetric soil water content ($ theta$) and bulk soil electrical conductivity (EC$ sb{ rm a}$). It has been found that the $ theta$ and EC$ sb{ rm a}$ values obtained by this method, on certain soils, require calibration. The purpose of this study was to monitor the effects of soil texture (most particularly the clay type and clay content) on $ theta$ and EC$ sb{ rm a}$ estimated by TDR. / Water content was measured, gravimetrically and by TDR, on packed columns of nine soil mixtures, composed of three clay types (Hydrite, Bentonite, and Ste. Rosalie clay) and coarse sand at three levels (8, 16, and 30% by weight) of these clay materials. Three replicates of each mixture (a total of 27 columns) were made to statistically establish the effect of the clay type and the clay content on $ theta$ and EC$ sb{ rm a}$ readings by TDR. It was found that the TDR overestimated $ theta$ for the Hydrite and Ste. Rosalie (Natural) materials but accurately predicted for the Bentonite materials, compared to gravimetric determinations. / Bulk soil electrical conductivity was simultaneously measured by two independent techniques, TDR and 4-probe, on the same soils. It was found that the clay types and clay contents have almost equal effects on the EC$ sb{ rm a}$ as measured by TDR and 4-probe techniques. It was found that the estimated EC$ sb{ rm a}$ values obtained by TDR and 4-probe methods for the fine-textured Bentonite materials were lower than those for the Hydrite and Ste. Rosalie materials at equal $ theta$ and EC$ sb{ rm W}$ (electrical conductivity of soil water).

The study of mechanical energy and electrical energy dissipation in cementitious materials can lead to development of high damping concrete for structural applications, and new non-destructive testing techniques for use on existing concrete structures. This research aims to improve mechanical damping properties of cementitious materials and determine durability parameters from complex permittivity measurements. Damping was improved by utilizing poromechanical effects, and by adding viscoelastic and nanometric inclusions. Poromechanics was utilized to model and predict damping on specimens designed to maximize poromechanical effects, and composite theory was used to predict composite bounds for the loss tangent, i.e. modeling the effects on damping due to the addition of viscoelastic inclusions. Experimental results indicated that substantial damping improvement can be realized by both poromechanical effects and adding novel inclusions into cement pastes. The models were able to predict experimentally measured damping as a function of loading frequency. The electrical energy dissipation in cementitious materials was studied by dielectric spectroscopy as a function of moisture state and pore structure/permeability. The results were compared to predictions from multiphase composite modeling, where the properties of the confined water was inversely determined and used to predict moisture content. It was found that moisture state of cementitious materials has a linear relation to the complex permittivity over a wide variety of frequency ranges. Composite model prediction indicated that permeability of saturated cementitious materials studied in this research is likely dependent on the amount of free water in the pores. Permeability can be inferred from the pore structure of the cement paste via complex permittivity measurements by conditioning cement paste at different levels of relative humidity.