[No abstract available] / Arts, Faculty of / History, Department of / Graduate

No abstract included. / Arts, Faculty of / History, Department of / Graduate

In the canyon where the Fraser River flows through the Cascade mountains, migrating salmon supported a large, dense native population. By 1850 the Hudson’s Bay Company had several forts on other parts of the Fraser River and its tributaries but found the canyon itself inaccessible. Prior to the gold rush, whites rarely ventured there. Discoveries of gold in Fraser River in 1856 drew the attention of outsiders and a rush of miners, and led eventually to permanent white settlement on mainland British Columbia. Contrary to much historiography, these were not foregone results. Instead, the gold rush was a complex process of negotiation and conflict among competing groups as they sought to profit from gold discoveries. The Hudson’s Bay Company sought to gain and retain control of the resource by incorporating it into its trade and by excluding outsiders. But miners arrived by the thousands, and the Company was forced to try to regulate miners’ access to the resource. However, as a group, miners were cohesive and self-reliant; they had little need for outside intervention. The Hudson’s Bay Company was unable to regulate them while pursuing its own ideas of profit. The British government subsequently revoked the Hudson Bay Company’s trade license, and proclaimed British Columbia a colony. In efforts to impose its own ideals of order on the gold fields, the government introduced a new colonial administration which, following a chain of command extending from London through Victoria to the Fraser, sought to organize the population in the spaces of the Fraser Canyon. Government authority was reinforced by the legal system’s flexible responses to the diverse population’s activities it deemed illegal. By studying the interactions of natives, miners, traders, administrators, and the legal system, I have attempted to untangle the ways in which white men negotiated their particular racist and masculinist ideals and sought to impose them in the spaces of the Fraser Canyon.

A study of the potassium status of some Lower Fraser Valley soils was undertaken in order to supply data which would aid in the interpretation of fertility experiments and chemical tests for available soil potassium. Since the rapid chemical tests for available potassium now used in the Lower Fraser Valley leave much to be desired, several promising methods were studied and compared to a standard ammonium acetate extraction gravimetric analysis method for determining exchangeable potassium. The Morgan and Spurway rapid methods for available potassium estimation were not found precise or accurate enough for the purposes of the study. A technique described by Peech and English, which involves extraction of available potassium with normal sodium acetate of pH4.8 and subsequent precipitation of potassium as the di-potassium sodium cobaltinitrite in formaldehyde-isopropyl alcohol solution was tested. A modification of this method was adapted to estimation by the photometer and results for exchangeable potassium, although lower, correlated well with those of the standard determination. A technique which is more rapid and better adapted to studies in which potassium is the only cation to be tested is that described by Bray, who recommends extraction with sodium nitrate and precipitation of potassium with sodium cobaltinitrite in ethyl alcohol solution and subsequent photometric determination. This method extracted slightly more potassium than that of Peech but also showed a high correlation with the standard method used. Both and Bray and Peech procedures were found adaptable to line chart estimation for routine soil testing work. The Bray method was compared to the standard ammonium acetate-gravimetric procedure in potassium fixation and release studies in limed and unlimed soils. Two upland soils and three recent alluvial soils, on which fertility experiments with oats had been conducted, were studied. A greenhouse experiment using lettuce was designed to indicate any existing relation between chemical studies and plant response. In the laboratory fixation was induced by alternately wetting and drying the soils at 110⁰ C. All soils were found to have high fixing potentials when measured by both extraction methods, although the fixation was higher when determined by the standard method. The effect of lime on fixation in both the laboratory and greenhouse soils was determined. The soils generally showed an apparent release of potassium when measured by the ammonium acetate-gravimetric method and a fixation by the sodium nitrate technique. These differences were considered to be due to the relative replacing powers of Na+ and NH+ when Ca++ or H+ dominate the exchange complex. Thus the extraction of potassium by Na+ may be inhibited when calcium is the complementary ion on the colloid. The potassium status of the upland soils was less affected by lime than the lowland soils when fixation or release due to lime was measured by either method. The soils studied failed to release any potassium from the fixed form when leached of their exchangeable potassium and stored for three months in a moist condition, or when wetted and dried at 110 C. No relation was found to exist between exchangeable potassium or the relative potassium fixing and supplying powers of the soils, and oat response to potassium in the field or lettuce growth in the greenhouse. / Land and Food Systems, Faculty of / Graduate

Assessments of the mesoscale variability of the insolation over the lower Fraser Valley have been hampered by the inadequate spatial resolution of the available pyranometric data. At present, the establishment of a dense ground-based observing network is economically infeasible. The adaptation of geostationary satellite data for estimating insolation is an attractive alternative. The ability of a simple physically-based model (Gautier et al., 1980) to resolve the hourly mesoscale insolation variability is evaluated. The satellite-based estimates are shown to be more coherent than the observed insolation. Discrepancies are attributed to the spatial averaging inherent in the satellite methodology. The estimates are found to be insensitive to spatial averaging down to a 3 x 3 pixel (about 13 km₂ ) scale. The effects of spatial averaging are believed to occur at smaller spatial scales. The satellite-based estimates generally display a good correspondence with the observed insolation. Maps of the mean hourly estimated insolation are obtained with a high degree of accuracy due to small systematic modelling errors. The inability of the model to distinguish between snow and cloud, and its sensitivity to variations in surface albedo introduce artifacts in maps of the clear sky insolation. On the other hand, the mesoscale variability of individual hourly fields cannot be resolved using 'the satellite-based approach. Errors for these estimates are so large that they obscure the variability of the insolation field. The usefulness of the mapping procedure appears to be limited to assessments of the average insolation. / Arts, Faculty of / Geography, Department of / Graduate

In the canyon where the Fraser River flows through the Cascade mountains, migrating salmon supported a large, dense native population. By 1850 the Hudson’s Bay Company had several forts on other parts of the Fraser River and its tributaries but found the canyon itself inaccessible. Prior to the gold rush, whites rarely ventured there. Discoveries of gold in Fraser River in 1856 drew the attention of outsiders and a rush of miners, and led eventually to permanent white settlement on mainland British Columbia. Contrary to much historiography, these were not foregone results. Instead, the gold rush was a complex process of negotiation and conflict among competing groups as they sought to profit from gold discoveries. The Hudson’s Bay Company sought to gain and retain control of the resource by incorporating it into its trade and by excluding outsiders. But miners arrived by the thousands, and the Company was forced to try to regulate miners’ access to the resource. However, as a group, miners were cohesive and self-reliant; they had little need for outside intervention. The Hudson’s Bay Company was unable to regulate them while pursuing its own ideas of profit. The British government subsequently revoked the Hudson Bay Company’s trade license, and proclaimed British Columbia a colony. In efforts to impose its own ideals of order on the gold fields, the government introduced a new colonial administration which, following a chain of command extending from London through Victoria to the Fraser, sought to organize the population in the spaces of the Fraser Canyon. Government authority was reinforced by the legal system’s flexible responses to the diverse population’s activities it deemed illegal. By studying the interactions of natives, miners, traders, administrators, and the legal system, I have attempted to untangle the ways in which white men negotiated their particular racist and masculinist ideals and sought to impose them in the spaces of the Fraser Canyon. / Arts, Faculty of / Geography, Department of / Graduate

Biogenic volatile organic compounds (VOCs) are a diverse class of hydrocarbon released during the normal physiological processes of some species of vegetation. These substances can participate in many chemical reactions and in some cases have potential to promote the formation of ground level ozone. The Fraser Valley located in southwestern British Columbia occasionally experiences these air pollution episodes during the summer. In order to effectively reduce the frequency and magnitude of these episodes, it is important that we understand the relative role of biogenic hydrocarbons from the abundant vegetated surfaces in the region. The thesis presents the results of measurements conducted on four common tree species in the lower Fraser Valley using a branch enclosure apparatus. Hydrocarbon emission rates from Cottonwoods trees were approximately one hundred times greater than those from coniferous trees and were dominated by the compound isoprene. Monoterpenoid emissions from four tree species were highly variable in magnitude and demonstrated no statistically significant relationship with temperature. Comparison of the observed results with a simple model from the literature shows relatively close agreement in the case of isoprene but poor agreement with monoterpene emissions. Results of these branch enclosure studies were extrapolated to larger scales to yield an areal emission rate assuming reasonable biomass densities. Isoprene measurements in this study reveal an areal emission rate approximately twenty times that of the assumed value in current emissions inventories. This discrepancy could be quite significant considering its magnitude and the possible sensitivity of the chemical reactions that produce ground level ozone to changes in isoprene concentration.

Biogenic volatile organic compounds (VOCs) are a diverse class of hydrocarbon released during the normal physiological processes of some species of vegetation. These substances can participate in many chemical reactions and in some cases have potential to promote the formation of ground level ozone. The Fraser Valley located in southwestern British Columbia occasionally experiences these air pollution episodes during the summer. In order to effectively reduce the frequency and magnitude of these episodes, it is important that we understand the relative role of biogenic hydrocarbons from the abundant vegetated surfaces in the region. The thesis presents the results of measurements conducted on four common tree species in the lower Fraser Valley using a branch enclosure apparatus. Hydrocarbon emission rates from Cottonwoods trees were approximately one hundred times greater than those from coniferous trees and were dominated by the compound isoprene. Monoterpenoid emissions from four tree species were highly variable in magnitude and demonstrated no statistically significant relationship with temperature. Comparison of the observed results with a simple model from the literature shows relatively close agreement in the case of isoprene but poor agreement with monoterpene emissions. Results of these branch enclosure studies were extrapolated to larger scales to yield an areal emission rate assuming reasonable biomass densities. Isoprene measurements in this study reveal an areal emission rate approximately twenty times that of the assumed value in current emissions inventories. This discrepancy could be quite significant considering its magnitude and the possible sensitivity of the chemical reactions that produce ground level ozone to changes in isoprene concentration. / Arts, Faculty of / Geography, Department of / Graduate

The Lower Fraser Valley, straddling the USA-Canada border in western North America, often experiences episodes of elevated tropospheric ozone in summertime. The meteorology governing those episode days is characterized by a stagnant high pressure system, light wind, strong insolation and the occurrence of sea breezes. To shed some light on the mesometeorology of ozone episodes in the LFV, this study employed the Regional Atmospheric Modelling System from Colorado State University, a non hydrostatic, three-dimensional mesoscale modelling system to simulate the detailed structure of air flows over the valley for one specific episode day. Significant code modifications have been made to enhance the model's ability to represent surface energy fluxes and predict surface temperatures in the surface of complex terrain and land-use patterns. Evaluation of the model performance was made against an extensive set of observation son the episode day. Pollutant transport on the modelling day was explored with a Lagrangian particle dispersion model. Specifically, forward trajectories were calculated for particles released at various locations in the Lower Fraser Valley and at different times. A systematic qualitative and quantitative model evaluation with the statistical method of Willmott showed that the model could adequately simulate the observed sea breeze another interactive terrain-induced flows such as slope wind and channel flow. Trajectory studies indicated that pollutant recirculations occurred largely from sources originating in the northwest part of the valley where most emission sources are located, and ended in a region where the highest ozone concentrations were observed. Recirculations were due to pollutants traveling with the interactive flows of sea breeze and upslope winds, and later being captured and directed back to the valley by the down slope winds. Particles released in other part of the valley all travelled outside the valley, having a minimal contribution to the episode buildup.

The Lower Fraser Valley, straddling the USA-Canada border in western North America, often experiences episodes of elevated tropospheric ozone in summertime. The meteorology governing those episode days is characterized by a stagnant high pressure system, light wind, strong insolation and the occurrence of sea breezes. To shed some light on the mesometeorology of ozone episodes in the LFV, this study employed the Regional Atmospheric Modelling System from Colorado State University, a non hydrostatic, three-dimensional mesoscale modelling system to simulate the detailed structure of air flows over the valley for one specific episode day. Significant code modifications have been made to enhance the model's ability to represent surface energy fluxes and predict surface temperatures in the surface of complex terrain and land-use patterns. Evaluation of the model performance was made against an extensive set of observation son the episode day. Pollutant transport on the modelling day was explored with a Lagrangian particle dispersion model. Specifically, forward trajectories were calculated for particles released at various locations in the Lower Fraser Valley and at different times. A systematic qualitative and quantitative model evaluation with the statistical method of Willmott showed that the model could adequately simulate the observed sea breeze another interactive terrain-induced flows such as slope wind and channel flow. Trajectory studies indicated that pollutant recirculations occurred largely from sources originating in the northwest part of the valley where most emission sources are located, and ended in a region where the highest ozone concentrations were observed. Recirculations were due to pollutants traveling with the interactive flows of sea breeze and upslope winds, and later being captured and directed back to the valley by the down slope winds. Particles released in other part of the valley all travelled outside the valley, having a minimal contribution to the episode buildup. / Arts, Faculty of / Geography, Department of / Graduate