Geography - Theses, Dissertations, and other Required Graduate Degree Essays

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Quantifying carbon cycle feedbacks under negative CO2 emissions

Date created: 
2021-07-09
Abstract: 

Land and ocean carbon sinks play a major role in regulating atmospheric CO2 concentration and climate. However, their future efficiency depends on feedbacks in response to changes in atmospheric CO2 concentration and climate. Since negative CO2 emissions technologies (NETs) are a key mitigation measure in emission scenarios consistent with global climate targets, understanding carbon cycle feedbacks under negative CO2 emissions is essential. This thesis investigates carbon cycle feedbacks under positive and negative CO2 emissions using an Earth system model driven with idealized scenarios of increasing and decreasing atmospheric CO2 concentration. Results suggest that carbon cycle feedbacks differ under positive and negative emissions, independently of the specific approach chosen for their quantification. The findings of this thesis provide insights into the approach best suited to quantify carbon cycle feedbacks under negative CO2 emissions, and into the role of these feedbacks in determining the effectiveness of NETs in reducing CO2 levels.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Kirsten Zickfeld
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.Sc.

Protecting privacy of semantic trajectory

Author: 
Date created: 
2021-06-29
Abstract: 

The growing ubiquity of GPS-enabled devices in everyday life has made large-scale collection of trajectories feasible, providing ever-growing opportunities for human movement analysis. However, publishing this vulnerable data is accompanied by increasing concerns about individuals’ geoprivacy. This thesis has two objectives: (1) propose a privacy protection framework for semantic trajectories and (2) develop a Python toolbox in ArcGIS Pro environment for non-expert users to enable them to anonymize trajectory data. The former aims to prevent users’ re-identification when knowing the important locations or any random spatiotemporal points of users by swapping their important locations to new locations with the same semantics and unlinking the users from their trajectories. This is accomplished by converting GPS points into sequences of visited meaningful locations and moves and integrating several anonymization techniques. The second component of this thesis implements privacy protection in a way that even users without deep knowledge of anonymization and coding skills can anonymize their data by offering an all-in-one toolbox. By proposing and implementing this framework and toolbox, we hope that trajectory privacy is better protected in research.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Nadine Schuurman
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.Sc.

United States bank migrations and deposit dollar concentrations

Author: 
Date created: 
2021-06-21
Abstract: 

This thesis incorporates four studies of the geography of bank offices and deposits in the United States (US). The research examines changes in retail bank branch proximity in neighborhoods, state banking law's role in motivating banks to relocate home offices, and the significance of tax avoidance driving deposits’ relocations. Chapter 1 introduces the framework and research questions that emerged from visually exploring geo-spatial banking data. Chapter 2 considers retail bank proximity changes in neighborhoods, classified by income, in urban Florida. It compares three pre- and post-financial crisis bank branch distributions: those merged with government assistance, those that merged unassisted, and those that did not merge. Did the branching decisions made by any of these bank groups disproportionately affect neighborhoods’ proximity to banks? Kruskal–Wallis and post hoc tests suggest that merged banks, which reduced total branches, did not disproportionately impact any neighborhood group. Statistically significant evidence suggests that unmerged banks, which increased total branches, disproportionately improved proximity to high-income areas, filling a spatial void created by closed offices of merged banks. The results suggest that banking regulators indirectly financed the rearrangement of banking offices, conflicting with federal policies aimed at maintaining bank offices near low-income neighborhoods. Chapter 3 examines the forces that drove a massive accumulation of deposits in Delaware and South Dakota, illuminating changes in banking regulation that lured banks from faraway places. Delaware and South Dakota broke longstanding public policy norms by creating bank-friendly regulation of three banking businesses: credit, insurance, and trusts, becoming a preferred legal “home office” for banks seeking regulatory relief. Chapter 4 traces the laws that helped induce Wall Street banks and other commercial firms to migrate to Utah. Utah expanded the scope of a historical anomaly in US banking regulation, the Industrial Loan Bank, which is exempt from longstanding regulatory norms separating banking from a non-banking business. The final chapter considers the lopsided share of deposits in Delaware, Nevada, South Dakota, and Utah after the flight of deposits from high-tax states. This research contributes to and suggests research possibilities on the oft-neglected subject of fiscal geography.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Geoff Mann
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) Ph.D.

Integration of GIS and soft computing for suitability evaluation of high-density urban development: The logic scoring of preference method

Author: 
Date created: 
2019-07-05
Abstract: 

The Logic Scoring of Preference (LSP) method is based on soft computing principles for complex spatial decision-making that integrates large number of criteria and capture human logic reasoning. The main objective of this study is to develop, implement and apply the LSP method in the Geographic Information System (GIS) environment for the land suitability evaluation for high-density urban development. Two different stakeholders, urban developer and urban planner, were considered. The geospatial datasets of Metro Vancouver Region, Canada, were used to implement the GIS-based LSP method. Several LSP aggregator groups have been compared and the results indicate that there are differences between the two stakeholder’s perspectives on suitable locations for high-rise urban development. The GIS-LSP method provides an effective way for identifying the best location for high density urban developments and thus contribute to more sustainable urban practices that can minimize the impact of the urban sprawl.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Suzana Dragićević
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.Sc.

Permaculture as a driver of social change? A textual analysis of permaculture with perspectives from coastal British Columbia

Author: 
Date created: 
2020-12-16
Abstract: 

My research aims to develop a deeper academic understanding of how permaculture contributes to alternative sustainability politics, focusing on how permaculture is envisioned and enacted as social change. Drawing on textual analysis, semi-structured interviews with permaculture practitioners, and feminist political ecology and critical food studies literatures I argue that while permaculture design is critical of industrial modes of production it remains rooted in universalized ideals of sustainability found in Western society. The creators of permaculture’s focus on apocalyptic narratives of peak oil, resource scarcity, and middle-class, individual-scale transformation positions sustainability as an issue universal to everyone while failing to account for global social, economic, and political inequalities. If permaculture’s goal is truly social change, practitioners need to look beyond permaculture towards more radical traditions that centre intersectional social justice. Without these critical interventions, permaculture risks becoming a white middle-class space that reproduces capitalist and colonial social relations.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Rosemary Collard
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.A.

Physics-based satellite-derived bathymetry for nearshore coastal waters in North America

Author: 
Date created: 
2020-11-13
Abstract: 

Accurate bathymetric information is fundamental to safe maritime navigation and infrastructure development in the coastal zone, but is expensive to acquire with traditional methods. Satellite-derived bathymetry (SDB) has the potential to produce bathymetric maps at dramatically reduced cost per unit area and physics-based radiative transfer model inversion methods have been developed for this purpose. This thesis demonstrates the potential of physics-based SDB in North American coastal waters. First the utility of Landsat-8 data for SDB in Canadian waters was demonstrated. Given the need for precise atmospheric correction (AC) for deriving robust ocean color products such as bathymetry, the performances of different AC algorithms were then evaluated to determine the most appropriate AC algorithm for deriving ocean colour products such as bathymetry. Subsequently, an approach to minimize AC error was demonstrated for SDB in a coastal environment in Florida Keys, USA. Finally, an ensemble approach based on multiple images, with acquisitions ranging from optimal to sub-optimal conditions, was demonstrated. Based on the findings of this thesis, it was concluded that: (1) Landsat-8 data hold great promise for physics-based SDB in coastal environments, (2) the problem posed by imprecise AC can be minimized by assessing and quantifying bias as a function of environmental factors, and then removing that bias in the atmospherically corrected images, from which bathymetry is estimated, and (3) an ensemble approach to SDB can produce results that are very similar to those obtained with the best individual image, but can be used to reduce time spent on pre-screening and filtering of scenes.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Nick Hedley
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) Ph.D.

Investigating the importance of methane for future climate change: wetland methane emissions, the permafrost carbon feedback, and methane mitigation

Date created: 
2021-01-18
Abstract: 

Methane (CH4) is a major greenhouse gas (GHG), second only to carbon dioxide (CO2) in the contribution to historical climate forcing. Yet, the level of understanding of how CH4 will influence the future climate remains low because CH4 processes are generally not represented in Earth system models used for future climate projections. The objective of this thesis is to investigate the importance of CH4 for future climate change with a focus on CH4 mitigation as well as wetland CH4 emissions from thawing permafrost soils, and their respective impact on global warming. The thesis includes a description of a new model for wetland CH4 emissions implemented in an Earth system model of intermediate complexity (EMIC) and applications of the EMIC (including a simplified representation of the CH4 cycle) to: (i) investigate the importance of CH4 mitigation to comply with stringent global warming limits, and (ii) project the additional warming due to wetland CH4 emissions from previously frozen carbon following gradual permafrost thaw over the next three centuries. Salient results of this thesis are: (i) immediate cuts in anthropogenic CH4 emissions, alongside CO2 mitigation, are needed to increase the likelihood of limiting global warming to 2°C above pre-industrial levels; (ii) the warming due to wetland CH4 emissions from thawing permafrost soils is projected to be small (<0.05°C) throughout the 21st century independent of the future anthropogenic emission scenario, (iii) the warming due to such permafrost CH4 emissions has the potential to increase substantially beyond the 21st century, reaching 0.09 (0.01-0.24) °C in the year 2300 under a scenario of high anthropogenic emissions. Overall, by incorporating a simplified representation of the CH4 cycle in Earth system model simulations, this thesis suggests that (i) delaying CH4 mitigation to after the year 2040 will constitute a challenge for limiting global warming to 2°C even if anthropogenic CO2 emissions were reduced aggressively, (ii) reducing anthropogenic GHG emissions will allow to limit the warming due to wetland CH4 emissions from thawing permafrost soils to well below 0.1°C over the next three centuries.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Kirsten Zickfeld
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) Ph.D.

Mixed reality interfaces in flood risk management

Author: 
Date created: 
2020-08-18
Abstract: 

Visualizations play a key role in analysing, understanding, and communicating risks of flooding and possible mitigation options. In particular, 3D visualizations are becoming increasingly prominent for risk communication. At the same time, there is a growing ecosystem of mixed reality interfaces that have potential to transform our interaction with 3D data and visualizations. This thesis outlines the potential of these tools and develops a set of mixed reality flood visualization prototypes that utilize capabilities of the state-of-the-art HoloLens 2 mixed reality system. By leveraging the representational and interactive capabilities provided by hand and eye-tracking, 3D displays, spatial mapping of user environment and positional tracking, these tools provide distinct and compelling experiences of 3D flood visualizations. To illuminate the potential of these tools to support meaningful practice, this thesis reflects on the user experience, hardware performance and usability of MR visualizations.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Nick Hedley
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.Sc.

High-resolution digital soil mapping for managed forests using airborne LiDAR data

Author: 
Date created: 
2020-07-14
Abstract: 

A goal of sustainable forest management using digital soil mapping (DSM) is to ensure that current and future generations have the best soil information so they can use forest resources wisely. This goal can be achieved using new technologies of generating digital soil maps and high-resolution light detection and ranging (LiDAR) data. Uncertainty in digital soil maps can be quantified using quantile regression (QR). The overall objective of this study is to generate several digital soil maps using different machine learning (ML) methods for forest management purposes and use a QR method to estimate their uncertainty. The study area is the Eagle Hill Forest (95 km2), located west of Kamloops, BC, Canada. Five soil properties were mapped and locations with soil erosion, displacement, and compaction and puddling hazards were displayed on maps and discussed. 90% prediction interval (PI) maps were produced and the performance of the QR method in uncertainty quantification of different ML models was illustrated by producing Prediction Interval Coverage Probability (PICP) plots.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Margaret Schmidt
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.Sc.

Exploring deep learning methods for analyzing land use change

Author: 
Date created: 
2019-07-03
Abstract: 

The process of land use change (LUC) results from human interactions with the natural environment to meet the needs from societal development. Growing population leads to the depletion of the land resource which entails environmental consequences from local to global scales. Advanced analytical methods can help with the understanding of the complexity of LUC process. They can further benefit sustainable land development. The main objective of this thesis research is to evaluate the deep learning (DL) methods such as convolutional neural networks (CNN) and recurrent neural networks (RNN) for classifying and forecasting LUC. The results demonstrated that the CNN-based LU classification models achieved the model accuracy of above 95%, while the RNN-based models for short-term LUC forecasting had 86% forecasting accuracy. This thesis contributes to advancing the methods for LUC analysis and improving the understanding of LUC process for sustainable land management.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Suzana Dragicevic
Department: 
Environment: Department of Geography
Thesis type: 
(Thesis) M.Sc.