Geography

Investigation of Dynamics of Particulate Transport under Varying Climate Conditions

Type:
Names:
Creator (cre): Schweighofer, Christopher John, Thesis advisor (ths): McKenna Neuman, Cheryl, Degree committee member (dgc): Power, Ian, Degree committee member (dgc): Aherne, Julian, Degree granting institution (dgg): Trent University
Abstract:

A key knowledge gap in aeolian transport research concerns the adjustment of saltation processes to the extreme conditions found within high-latitude regions. A series of wind tunnel experiments were carried out under full climate control and over a wide range in humidity. Particle entrainment and transport within shearing flows of varied wind speed were monitored over beds of varied temperature, and ice content to determine their affect on 1) particle trajectory, 2) saltation cloud height, 3) particle velocity, 4) surface erosivity, 5) mass transport rate and 6) vertical dust flux. Particles were found to have higher velocities over cold beds than dry beds. With a 3% increase in bed moisture content, a significant increase in particle velocity was measured. Fewer particles are ejected from a bed with moisture than a dry bed. The mass transport rate was measured to be 23% higher at -10 degrees Celsius compared to 30 degrees Celsius.

Author Keywords: Aeolian processes

2024

The Influence of Atmospheric Circulation on Snowmelt and Carbon Fluxes in the Canadian Low Arctic

Type:
Names:
Creator (cre): Braid, Alexandra Stephanie Lind, Thesis advisor (ths): Lafleur, Peter, Degree committee member (dgc): Hember, Robert, Degree committee member (dgc): Aherne, Julian, Degree granting institution (dgg): Trent University
Abstract:

This study examines the atmospheric (synoptic) controls on snowmelt and snow-free season carbon dioxide (CO2) fluxes at Daring Lake, Northwest Territories. Atmospheric circulation patterns were derived from 500 hPa geopotential height and classified using the self-organizing maps artificial neural network. Snowmelt timing was not found to be influenced by atmospheric circulation patterns or large-scale teleconnection indices, but a shift from meridional to zonal atmospheric circulation marked the transition from pre-melt to melt period. Multiple linear regression identified heating degree days and incoming solar radiation as the most important meteorological predictors of melt length; however, the model would have benefitted from additional variables. Analysis of CO2 (net ecosystem exchange, NEE) during the snow-free season highlighted a strong correlation between NEE and temperature anomalies. Like the snowmelt period, no atmospheric circulation patterns were found to significantly influence NEE; however, these findings prompt further questions regarding snowmelt and CO2 fluxes in the Canadian low Arctic.

Author Keywords: atmospheric circulation, carbon fluxes, net ecosystem exchange, self-organizing maps, snowmelt, synoptic patterns

2024

The Effects of Agricultural Land Use Change on Nitrogen and Phosphorus in North Shore Lake Ontario Tributaries

Type:
Names:
Creator (cre): DeBues, Max, Thesis advisor (ths): Eimers, Catherine, Degree committee member (dgc): Watmough, Shaun, Degree committee member (dgc): Mohamed, Mohamed, Degree committee member (dgc): Mueller, Jessica, Degree granting institution (dgg): Trent University
Abstract:

Row crop agriculture and associated land use practices including tile drainage and conservation tillage have been cited as a probable cause of re-emerging eutrophication in the lower Great Lakes. In this thesis, I sought to quantify and evaluate the effect of agricultural land cover and land use changes on total phosphorus (TP) and nitrate-nitrogen (NO3-N) concentrations and export in north shore Lake Ontario tributaries. This included (a) a long-term data analyses at 12 large watersheds (47 to 278 km²) using historical land cover and water quality data (1971-2010), and (b) a space-for-time study examining 12 small sub-catchments (< 8 km²) with majority (> 50%) row crop, pasture, or forest cover. Concentrations of TP were greatest in urbanized watersheds and declined particularly during the first decades of the study period, while NO3-N concentrations were greatest and steadily increased in agricultural catchments with increasing row crop cover. The space-for-time approach revealed that TP concentrations were similar across agricultural land uses and that export was most dependent on runoff. Meanwhile, NO3-N concentrations and export were greatest in row crop catchments and were positively related to row crop area. These results suggest that increases in row crop cover and associated agricultural practices including increased nutrient amendments and tile drainage may be responsible for increased NO3-N concentrations and export in northern Lake Ontario tributaries.

Author Keywords: agriculture, Lake Ontario, nitrogen, phosphorus, streams, Water quality

2022

Local Immigration Partnerships: A Case Study in Regional Governance of Durham Region, Ontario

Type:
Names:
Creator (cre): Cullen, Blair, Thesis advisor (ths): Skinner, Mark, Degree committee member (dgc): Greene, Jonathan, Degree committee member (dgc): Dart, Ray, Degree granting institution (dgg): Trent University
Abstract:

Introduced as part of the Canada-Ontario Immigration Agreement, Local Immigration Partnerships (LIPs) mark a fundamental shift in local settlement policy. To address the gap in knowledge about the implications of this policy change, this thesis research features a case study of Durham Region's LIP. Objectives were designed to examine the impact of Durham's LIP by interviewing 52 key-informants within six sectors involved in settlement and integration. Findings indicate an effective application of the LIP policy with participants pointing to the LIP's vital role in bringing Welcome Centres to Durham, increasing the attention and profile of immigration issues and improving governance relations amongst different sectors in settlement and integration. A product of local circumstances, the LIP has engaged in a quasi-advocacy role educating mainstream service providers and institutions on how to respond to a diversifying population. Results contribute to the relatively under-studied but growing knowledge of the LIP policy while demonstrating that the localization of immigration policy under the appropriate terms can be successful.

Author Keywords: Governance, Integration, Local Immigration Partnerships, Ontario, Regionalization, Settlement

2014

Sustainable Development and Environmental Security in the Canadian Arctic: Inuvik and Tuktoyaktuk

Type:
Names:
Creator (cre): Barnes, Justin, Thesis advisor (ths): Nicol, Heather, Degree committee member (dgc): Bocking, Stephen, Degree granting institution (dgg): Trent University
Abstract:

This study identifies and examines interlinkages between climate change and sustainable development, environmental security, and adaptive capacity through a case study of two communities in the Inuvialuit Settlement Region: Inuvik and Tuktoyaktuk. It seeks to understand how these two communities perceive climate change and define sustainable development, particularly in relation to oil and gas development. This thesis discusses the constraints that may be arising for local communities to benefit from emerging opportunities due to competing notions of sustainable development and environmental security. The findings indicate how notions of environmental security and sustainable development act upon multiple levels to impact the adaptive capacity of communities in the Arctic. The general findings also suggest that regionally specific understandings of sustainable development, sustainability, and environmental security need to be acknowledged in order to develop successful governance coordination and cooperation strategies and paradigms related to economic, social, infrastructure and environmental issues in the NWT and the Canadian Arctic.

Author Keywords: Arctic, Beaufort Sea, climate change, Environmental Security, Inuvialuit, Sustainable Development

2020

Something out of Nothing? Place-based Resilience in Rural Canadian Youth

Type:
Names:
Creator (cre): Hurlington, Kingsley G., Thesis advisor (ths): Skinner, Mark W, Degree committee member (dgc): Hill, Stephen, Degree committee member (dgc): Patrick, Donna, Degree committee member (dgc): Russell, Elizabeth, Degree committee member (dgc): Wiles, Janine, Degree granting institution (dgg): Trent University
Abstract:

This dissertation explored how rural communities enhance the capacity of youth to both navigate and negotiate healthy identities and well-being in the context of social ecological resilience. Resilience refers to the capacity for individuals to have good outcomes in spite of exposure to significant adversity. Rural communities are often identified as places of deficit both in scholarly literature and in general social discourse which can constitute adversity. Given the importance of place as a social determinant of health, rural communities can have a notable impact on the positive development of adolescent identity and well-being of the youth that reside within them.

Drawing on the concept of social ecological resilience which draws attention to the importance of environments and relationships to support development, this project engaged with high school aged adolescents (14 to 18 years old) from Haliburton County in Central Ontario. Leveraging mixed model methods, the project featured both quantitative and qualitative approaches. There were 63 participants (33 male, 28 female and 2 non-binary) for the quantitative phase of the research which made use of the Child and Youth Resilience Measure survey instrument. The second phase of the research was qualitative and featured 14 participants who engaged in six focus groups. The focus groups provided context specific awareness of place-based factors which participants found supportive in their development.

The results indicated that while the overall resilience scores for the community were lower than the national average (t(62) = 3.20, p <0.01), some study participants found the community to be resilience bolstering. Specifically, participants recognized the importance of supportive people, an awareness of an enriched sense of community, and a powerful sense of the value of nature and the outdoors to be the most significant aspects for the development of their resilience.

The results indicate that rural youth are not naïve to the complexity of their circumstances but are able to use their rural contexts to develop the capacity to negotiate and navigate towards healthy identities and well-being.

Author Keywords: Adolescent, Place-based, Resilience, Rural, Social Ecological, Youth

2019

Volunteer Experiences of Place-making for Sustainable Community Development

Type:
Names:
Creator (cre): Kosurko, An, Thesis advisor (ths): Skinner, Mark, Degree committee member (dgc): Dart, Ray, Degree granting institution (dgg): Trent University
Abstract:

This thesis explores the experiences of volunteers who came together to redevelop an

abandoned convent into The Mount Community Centre (The Mount) for the purpose of

sustainable community development. The goal of the research was to explore the

relational processes of place-making at The Mount, to be achieved through two

objectives: first, to describe the nature of collaboration among volunteers in place at The

Mount; and second, to understand the experience of volunteers through their narratives

and descriptions, with respect to the influence of The Mount as a place. Methods

employed were participant observation and key-informant interviews with 24 participants

conducted using a video-documentary approach. The result was a community-based,

qualitative case study comprised of volunteer voices, in their collective narrative of

experience of The Mount's development trajectory. A thematic analysis of volunteer

narratives indicated patterns of connectivity and the expansion of relational networks of

place, implicated in strategic approaches in three experiential phases of Daring, Erring,

and Groundswell along the development's trajectory. In demonstrating how place

influences community organization to address needs, The Mount provides an example for

future inquiry that contributes to the advancement of knowledge in discussions of

voluntarism, place, and sustainable community development.

Keywords: Voluntarism, place-making, sustainable community development,

community-based research

Author Keywords: community-based research, Non-profit sector, Place, Place-making, Sustainable-community development, Voluntarism

2017

A wind tunnel based investigation of three-dimensional grain scale saltation and boundary-layer stress partitioning using Particle Tracking Velocimetry

Type:
Names:
Creator (cre): O'Brien, Patrick, Thesis advisor (ths): McKenna Neuman, Cheryl, Degree committee member (dgc): McConnell, Sabine, Degree committee member (dgc): Lafleur, Peter, Degree granting institution (dgg): Trent University
Abstract:

Aeolian transport of sand particles is an important geomorphic process that occurs over a significant portion of the earth's land surface. Wind tunnel simulations have been used for more than 75 years to advance the understanding of this process; however, there are still several principles that lack validation from direct sampling of the sand particles in flight. Neither the three-dimensional dispersion of, nor the momentum carried by particles in flight have been properly measured. This has resulted in the inability to validate numerical particle dispersion models and the key boundary-layer momentum partitioning model that serves as the framework for understanding the air-sand feedback loop. The primary impediment to these measurements being made is a lack of tools suited for the task. To this end, this PhD aims to improve existing particle tracking technology, thus enabling the collection of particle measurements during wind tunnel experiments that would address the aforementioned knowledge gaps.

Through the design and implementation of the Expected Particle Area Searching method, a fully automated particle tracking velocimetry system was developed with the capability to measure within ½ grain diameter of the bed surface under steady state transport conditions. This tool was used to collect the first 3-D data set of particle trajectories, from which it was determined that a mere 1/8th of sand transport is stream aligned and 95% is contained within ± 45o of the mean wind direction. Particles travelling at increasing spanwise angles relative to the stream aligned flow were found to exhibit different impact and ejection velocities and angles. The decrease in the number of particles with increasing height in the saltation cloud, very close to the bed is observed to transition from a power to a linear relation, in contrast to previous literature that observed an exponential decay with coarser vertical resolution.

The first direct measurements of particle-borne stress were captured over a range of wind velocities and were compared with earlier fluid stress measurements taken using Laser Doppler Anemometry. In support of established saltation theory, impacting particle momentum is found to contribute strongly to particle entrainment under equilibrium conditions. In opposition to established theory, however, particle-borne stress was found to reach a maximum above the surface and does not match the change in air-borne stress with increasing distance from the surface. Near surface splashed particles, measured herein for the first time, appear to play a greater role in stress partitioning than previously thought. This study suggests that research is needed to investigate the role of bed load transport on stress partitioning, to differentiate between airborne trajectory types, and to develop particle tracking tools for field conditions.

Author Keywords: Aeolian Transport, Eolian Transport, Particle Tracking Velocimetry, Saltation, Stress Partitioning, Wind Tunnel Simulation

2018

'This is where the poetry comes out': Examining the Peterborough Poetry Slam as resistant space-making

Type:
Names:
Creator (cre): Baldwin, Melissa, Thesis advisor (ths): Chazan, May, Degree committee member (dgc): Chivers, Sally, Degree granting institution (dgg): Trent University
Abstract:

Since 1984, poetry slams have emerged as a politicized expressive movement of performing the personal and political through poetry competitions. Slams are also discursively spatialized, often represented as "spaces" that are "safe," "inclusive," etc. In this thesis, I investigate how, why, and to what effect the Peterborough Poetry Slam produces, consolidates, and challenges such "resistant spaces." Drawing on interviews and participant observation, I consider how the slam's reiterative practices facilitate its space-making by encouraging performances that resist, reimagine, and sometimes inadvertently reify dominant societal norms. I argue that this space-making is imperfect yet productive: though not resistant space in any straightforward or static way, the slam continuously produces possibilities to challenge norms and confront power. This thesis contributes to scholarship on performative space and creative resistance movements. In an era when political resistance to power structures is often silenced, this research offers insights of potential significance to other resistant space-makings.

Author Keywords: Nogojiwanong Peterborough, performative space, poetry slam, resistance, space-making, spoken word

2017