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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Teleconnections between ENSO events and growing season precipitation on the Canadian Prairies

Bonsal, Barrie Richard 01 January 1996 (has links)
Teleconnections between ENSO events and growing-season precipitation variations on the Canadian Prairies are examined. Correlation and composite analyses indicate that between 1948 and 1991, El Nino events were associated with more frequent extended dry spells. Conversely, La Nina events coincided with fewer extended dry spells. Both relationships occurred during the third growing season following the onset of the ENSO events (i.e. approximately a 10-season or 30-month lag). A series of atmosphere - ocean teleconnections over the Pacific Ocean including Pacific North America (PNA) circulation patterns, North Pacific sea-surface temperature anomalies and upper-atmospheric circulation anomalies were found to result in growing-season precipitation variations over the Canadian Prairies. Results of this analysis are incorporated into a conceptual model which may form the basis of a long-range forecasting technique of growing-season precipitation variations on the Canadian Prairies.
12

Hydrological regime changes in a Canadian Prairie wetland basin

2015 July 1900 (has links)
The hydrology of the Canadian Prairies has been well described in the scientific literature. 20th C observations show that snowmelt over frozen soils accounted for over 80% of the annual runoff, and streamflow hydrographs peaked in April and ceased in May due to a lack of runoff or groundwater contributions. Since then, the region has undergone rapid changes in land use and climate, both which affect streamflow generating processes. This study evaluates the detailed hydrological impact of regional changes to climate on an instrumented research catchment, the Smith Creek Research Basin (SCRB); an unregulated, wetland and agriculture dominated prairie catchment in south-eastern Saskatchewan. Wetlands have been drained for decades, reducing wetland extent by 58% and maximum storage volume by 79%, and increasing drainage channels lengths by 780%. Long term meteorological records show that there have been gradual changes to the climate: though there are no trends in annual precipitation amount, increasing temperatures since 1942 have brought on a gradual increase in the rainfall fraction of precipitation and an earlier snowmelt by two weeks. In the summer months, the number of multiple day rainfall events has increased by 5 events per year, which may make rainfall-runoff generation mechanisms more efficient. Streamflow records show that annual streamflow volume and runoff ratios have increased 14-fold and 12-fold, respectively since 1975, with major shifts in 1994 and 2010. Streamflow contributions from rainfall-runoff and mixed-runoff regimes increased substantially. Snowmelt runoff declined from 86% of annual discharge volume in the 1970’s to 47% recently while rainfall runoff increased from 7% to 34%. Annual peak discharge tripled over the period from 1975 to 2014, with a major shift in 1994, while the duration of flow doubled in length to 147 days after a changepoint in 1990. Recent flooding in the SCRB has produced abnormally large streamflow volumes, and flooding in June 2012 and 2014 was caused solely by rainfall, something never before recorded at the basin. Although the observed changes in climate and wetland drainage are substantial, it is unlikely that a single change can explain the dramatic shifts in the surface hydrology of the SCRB. Further investigation using process hydrology simulations is needed to help explain the observed regime changes.
13

Voice Map Trekking

Klassen, Michael John 21 January 2008 (has links)
The site analysis and mapping methods in the design and planning professions follow a standardized quantitative and qualitative analyis of place that favors a design process which can limit creativity and render it difficult to do anything with the normative. This work is an exploration of the development of a design approach and method that uses voice mapping as a basis for design. The voice maps contain oral histories and personal accounts of landscape experiences. Voice mapping is employed not only as a method or for site analysis but also as a generator or ideas. Voice Map Trekking is explored through a trek in the Canadian Arctic and across the Canadian Prairies. Two specific landscapes were chosen as bases for testing concepts - one near St. Gertrude SK and the other near Morinville AB.
14

Genetic mapping and physiological characterization of water-use efficiency in barley (Hordeum vulgare L.) on the Canadian Prairies

Chen, Jing Unknown Date
No description available.
15

Developing a sense of place in rural Alberta: experiences of newcomers

Plaizier, Heather Mae Unknown Date
No description available.
16

The black prairies: history, subjectivity, writing

Vernon, Karina J. 24 April 2008 (has links)
This dissertation contributes to the fields of Canadian literature and black cultural studies in Canada a new regional archive of literature, the black prairie archive. It unearths and brings critical attention, for the first time, to the unknown history and cultural production of late nineteenth- and early twentieth-century black pioneer writers on the Canadian prairies, and connects this historical literature to the work of contemporary black prairie authors. The black prairie archive thus brings together one hundred and thirty five years of black writing on the prairies, from 1873-2008. Theorized in terms of what Pierre Nora calls a lieu de mémoire, or a site of memory, the black prairie archive operates as a site of collective black-inflected memory on the prairies. It retrieves memory of a repressed but important black history and culture and brings it into consciousness of the present historical moment. In its ability to remember what has been repressed and forgotten, the archive functions as a literary counterhistory, calling attention to the aggressive exclusions and erasures involved in the historical, social, critical, and legal construction of the prairies as an ideological—not a geographic—space in relation to race. In addition to bringing a new regional black literature to light, this study offers the black prairie archive as a discursive formation that points to a new methodology, a methodology capable of addressing the limits of certain critical debates in Canada. Specifically, it offers a strategy for theorizing black belonging and territoriality in terms other than the problematic metaphors of black indigeneity; for reading the regional particularities of black prairie literature and subjectivity; and for overcoming the impasse at the centre of black Canadian cultural studies, represented by the debate between Rinaldo Walcott and George Elliott Clarke, regarding which model, the archival or diasporic, best articulates the space of black Canada. The black prairie archive demonstrates how the archive can become a critical, activist, anti-national strategy for recovering repressed black histories, literatures, and presences.
17

Developing a sense of place in rural Alberta: experiences of newcomers

Plaizier, Heather Mae 11 1900 (has links)
This narrative inquiry uses the talking circle, a discourse process indigenous to the North American prairies, to explore the experiences of recent international migrants to rural Alberta. The immediate intention is to address questions of rural revitalization and the creation of welcoming communities. At a deeper level, it explores the role of history, cultural negotiation, and power relations in community development. It examines place as a critical element of human experience, which has been severed under modern economic regimes. Recommendations for how we might best respond to rural migration challenges include processes for listening and responding to needs, for building trustworthy relationships, and a call to recognize Aboriginal history. Findings also point to the importance of facilitating options for migrants with temporary status in a transient global context. The study advises that learning through attentive intercultural discourse could be integral to recreating democratic communities and establishing sense of place. / Adult Education
18

Canopy Architecture and Plant Density Effect in Short-Season Chickpea (Cicer arietinum L.)

Vanderpuye, Archibald W. 22 September 2010
Chickpea (Cicer arietinum L.) production on the semi-arid Canadian Prairies is challenging due to a short growing season and low and variable moisture. The current recommended chickpea population density of 44 plants m-2 is based on preliminary studies and a narrow range of 20 to 50 plants m-2. The aims of this study were to i) determine optimum population density of varying chickpea canopy types, i.e., leaf type and growth habit, by investigating seed yield responses at 30 to 85 plants m-2 and ii) identify desirable parental traits for breeding programs by assessing growth and yield parameter responses to varying leaf types and growth habits at a range of population densities. Field experiments were conducted from 2002 to 2005. Canopy measurements and calculated variables included light interception, biomass, growth rate, seed yield, harvest index, ascochyta blight severity and radiation- and water use efficiencies. The plant density which produced the highest seed yield when averaged over years for each location for each treatment revealed that a plant density of at least 55 plants m-2 produced a 23% to 49% seed yield increase above that of the currently recommended plant density. This indicates that a higher seed yield average over the long term in spite of periodic low seed yield episodes will be more profitable to producers. Increasing plant density increased lowest pod height significantly in all except one location-year but did not explicitly increase ascochyta blight severity or decrease individual seed size. This suggests that increasing the recommended chickpea plant density on the Canadian Prairies will increase seed yield but would neither negatively impact individual seed size nor ascochyta blight severity, especially, when combined with good agronomic practices. Fern-leaved cultivars had significantly higher maximum intercepted light (62 to 91%), seed yield (136 to 369 g m-2), harvest index (0.33 to 0.53), yield-based water use efficiency (0.56 to 1.06 g m-2 mm-1) and lower ascochyta blight severity (3 to 27%) than the unifoliate cultivars in all location-years. The fern-leaved cultivars also tended to show significantly higher cumulative intercepted radiation (221 to 419 MJ m-2) and biomass (306 to 824 g m-2) but leaf type showed no consistent effect on radiation use efficiency. Cultivars with bushy growth habit generally performed better regarding maximum intercepted light (62 to 90%), cumulative intercepted radiation (233 to 421 MJ m-2), biomass (314 to 854 MJ m-2), seed yield (120 to 370 g m-2), harvest index (0.37 to 0.50), yield-based water use efficiency (0.56 to 1.06 g m-2 mm-1) and ascochyta blight severity (7 to 36%) than the erect cultivars. The overall performance of the spreading cultivar was generally intermediate between the bushy and erect cultivars except for ascochyta blight severity where the spreading cultivar exhibited significantly lower disease severity (3 to 36%). Radiation use efficiency was generally not influenced by growth habit. Increasing plant population density generally increased intercepted light, biomass and cumulative intercepted radiation on each sampling day after seeding resulting in a general increase in seed yield. Harvest index, however, remained constant and ascochyta blight severity was generally stable but radiation use efficiency decreased with increasing population density. Chickpea cultivars with fern leaves and bushy growth habit at higher than currently recommended population densities would best utilize the limited resources of the short-season Canadian prairie environment to maximize and stabilize seed yield.
19

Canopy Architecture and Plant Density Effect in Short-Season Chickpea (Cicer arietinum L.)

Vanderpuye, Archibald W. 22 September 2010 (has links)
Chickpea (Cicer arietinum L.) production on the semi-arid Canadian Prairies is challenging due to a short growing season and low and variable moisture. The current recommended chickpea population density of 44 plants m-2 is based on preliminary studies and a narrow range of 20 to 50 plants m-2. The aims of this study were to i) determine optimum population density of varying chickpea canopy types, i.e., leaf type and growth habit, by investigating seed yield responses at 30 to 85 plants m-2 and ii) identify desirable parental traits for breeding programs by assessing growth and yield parameter responses to varying leaf types and growth habits at a range of population densities. Field experiments were conducted from 2002 to 2005. Canopy measurements and calculated variables included light interception, biomass, growth rate, seed yield, harvest index, ascochyta blight severity and radiation- and water use efficiencies. The plant density which produced the highest seed yield when averaged over years for each location for each treatment revealed that a plant density of at least 55 plants m-2 produced a 23% to 49% seed yield increase above that of the currently recommended plant density. This indicates that a higher seed yield average over the long term in spite of periodic low seed yield episodes will be more profitable to producers. Increasing plant density increased lowest pod height significantly in all except one location-year but did not explicitly increase ascochyta blight severity or decrease individual seed size. This suggests that increasing the recommended chickpea plant density on the Canadian Prairies will increase seed yield but would neither negatively impact individual seed size nor ascochyta blight severity, especially, when combined with good agronomic practices. Fern-leaved cultivars had significantly higher maximum intercepted light (62 to 91%), seed yield (136 to 369 g m-2), harvest index (0.33 to 0.53), yield-based water use efficiency (0.56 to 1.06 g m-2 mm-1) and lower ascochyta blight severity (3 to 27%) than the unifoliate cultivars in all location-years. The fern-leaved cultivars also tended to show significantly higher cumulative intercepted radiation (221 to 419 MJ m-2) and biomass (306 to 824 g m-2) but leaf type showed no consistent effect on radiation use efficiency. Cultivars with bushy growth habit generally performed better regarding maximum intercepted light (62 to 90%), cumulative intercepted radiation (233 to 421 MJ m-2), biomass (314 to 854 MJ m-2), seed yield (120 to 370 g m-2), harvest index (0.37 to 0.50), yield-based water use efficiency (0.56 to 1.06 g m-2 mm-1) and ascochyta blight severity (7 to 36%) than the erect cultivars. The overall performance of the spreading cultivar was generally intermediate between the bushy and erect cultivars except for ascochyta blight severity where the spreading cultivar exhibited significantly lower disease severity (3 to 36%). Radiation use efficiency was generally not influenced by growth habit. Increasing plant population density generally increased intercepted light, biomass and cumulative intercepted radiation on each sampling day after seeding resulting in a general increase in seed yield. Harvest index, however, remained constant and ascochyta blight severity was generally stable but radiation use efficiency decreased with increasing population density. Chickpea cultivars with fern leaves and bushy growth habit at higher than currently recommended population densities would best utilize the limited resources of the short-season Canadian prairie environment to maximize and stabilize seed yield.

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