Geography and Environmental Management

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This is the collection for the University of Waterloo's Department of Geography and Environmental Management.

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Assessing changes in peatland plant community functions following seismic line disturbance of different ages
(University of Waterloo, 2024-09-25) Bao, Jie
Seismic lines are linear clearings created for petroleum exploration mostly across boreal peatlands and forests in northwestern Canada. Seismic line disturbance has resulted in significant environmental impacts, including changes in plant composition, predator-prey dynamics, and hydrological conditions. There are more than 1.8 million km of seismic lines in Alberta, Canada, and they often remain visible even after decades. Despite the extensive occurrence of seismic lines, their effects on peatland plant community functions remain poorly understood. This study uses a trait-based approach to explore the impact of seismic line disturbance on peatland plant community functions. We measured key morphological plant traits, such as specific leaf area (SLA) and leaf dry matter content (LDMC), along with leaf chemical composition, such as nitrogen (N) and carbon (C). Vegetation cover was also assessed to understand species distribution across disturbed and undisturbed areas. Statistical analyses, including multivariate methods, were conducted to determine how seismic line disturbance influences plant traits and community composition. The results indicate that seismic lines are on a positive recovery trajectory, as reflected by the similarities in both plant community composition and plant traits between undisturbed areas and the areas that have naturally regenerated for about 30 years. However, it does not imply that the peatlands have returned to their pre-disturbance state after three decades. The findings of this study have important implications for the restoration of boreal peatlands disturbed by seismic lines. While restoration strategies like mounding may accelerate ecosystem recovery, these interventions themselves can cause further disturbance. Therefore, it is crucial to balance the time required for natural recovery with the potential disturbances introduced by restoration efforts.
Disentangling and Demystifying Illegal Wildlife Trade and Crime Convergence
(University of Waterloo, 2024-09-24) Anagnostou, Michelle
Illegal wildlife trade represents a significant and growing form of organized crime. In recent years, illegal wildlife trade has been increasingly reported as being perpetuated by the same people trafficking in drugs, humans, and arms, and committing acts of terrorism, a phenomenon often labelled “crime convergence”. However, limited empirical research has been conducted to understand the extent and nature of these convergences. This doctoral dissertation addresses that knowledge gap. This dissertation makes significant advancements in crime convergence theory and enriches the global empirical data. Through four interrelated studies, this dissertation illustrates that illegal wildlife trade is a complex form of crime that relates to a myriad of other serious and organised crime activities. The results also indicate that convergences themselves can take many forms, and therefore should be considered with a nuanced lens. The dissertation advocates for the adoption of more collaborative approaches to mitigate converging crimes. The studies also highlight that tectonic shifts are required to prioritise illegal wildlife trade more appropriately, and to combat the dynamic and innovative strategies of wildlife traffickers more effectively.
Identifying the Imprint of Climate Change on Low-Arctic Rivers from Planform Changes of the Colville River, Alaska
(University of Waterloo, 2024-09-24) Serrano, Pedro
The undeniable effect of climate change is prevalent in countless number of natural processes occurring across our planet, particularly within the circumpolar region. These climatic shifts have had an impact on internal and external forces that drive river movement. Hence, channel activities within these regions would, presumably, also change in response. Using the Colville River, situated in northern Alaska, USA, as a study site, the research first identifies the climatological trends occurring within the region. Temperature, precipitation, and discharge from the year 2002 to 2019 are examined to identify how these internal and external factors have changed throughout the years. Additionally, channel activities of two reaches within the river are also calculated within the same period using Landsat data. These variables are then correlated amongst each other to identify how one factor influences the other. Trends are captured on both a continuous (short-term) and a yearly (long-term) timeframe, whereby the continuous timeframe presents the data in a monthly sequential period from 2002 to 2019 while the yearly timeframe compares the data of each month across the years. Finally, the same approach was completed using Planet satellite imageries, where data is available, to verify the result. The findings show an overall increase in temperature primarily during the winter months, increase in frequency of precipitation towards the more recent years, and both an increase and decrease in discharge during the freezing and thawing period, respectively. Furthermore, the calculation shows a strong positive correlation between discharge and temperature (r = 0.63, r2 = 0.39, p-value = 4.64e-17) for the continuous, short-term, timeframe and a relatively strong negative correlation (r = -0.57, r2 = 0.32, p-value = 1.88e-5) for the yearly, long-term, timeframe. The positive correlation between the two variables in the short-term timeframe shows the seasonal relationship between temperature and discharge, whereby as the temperature increases, discharge also increases in response. Interestingly, however, the long-term timeframe suggests that as the temperature increases, discharge decreases in response. This was identified as the effect of climate change that is caused by the increase in temperature during the freezing months. Discharge is starting to take place throughout the year, therefore it is hypothesized that during the thawing months most ice have already melted which results in an overall decrease in discharge during the freezing months. And given the relatively strong positive correlation of discharge and channel activity for the short-term timeframe (Reach A: r = 0.62, r2 = 0.62, p-value = 1.02e-16 and Reach B: r = 0.68, r2 = 0.46, p-value = 2.65e-19), it is expected that channel movement will soon follow such decrease in discharge trend in the long run. These findings suggest that semi-arctic braided rivers, the Colville River in particular, are transitioning to river movements more similar to rivers situated in temperate climate, whereby activity is not only prevalent during the thawing months but will soon be identifiable throughout the year.
Assessing Tree Carbon Estimates from Remotely Piloted Aircraft-Based LiDAR: A Comparison of Quantitative Structural Models and Allometric Scaling with In-Situ DBH Measurements
(University of Waterloo, 2024-09-23) Liu, Chenxi
Forest carbon storage estimation is critical for global climate change mitigation efforts, as forests play a vital role in the carbon cycle. This study investigates the accuracy of using Remotely Piloted Aircraft (RPA)-based LiDAR for estimating tree Diameter at Breast Height (DBH) and carbon storage through 3D tree modeling techniques. Two Quantitative Structure Models (QSM) — TreeQSM and AdQSM were used to virtually reconstruct trees and estimate tree and forest carbon stocks, with comparisons made to in-situ DBH measurements and traditional Allometric Scaling Models (ASMs), including self-developed allometric equation database and i-Tree Eco. Data were collected from two forest sites with different tree densities in Ontario, Canada, under leaf-on and leaf-off conditions. Result indicates that AdQSM generally outperformed TreeQSM in estimating DBH, particularly in less dense forests and during leaf-off season, where the correlation with in-situ DBH measurements improved. Despite variation in results from the two models, RPA-based LiDAR demonstrated potential as a scalable and non-destructive tool for forest carbon estimation, providing a foundation for future advancements in localized ASMs. The findings highlight the importance of accurate tree parameter extraction for forest carbon accounting, aligning with global efforts in climate change mitigation and sustainable forest management.
Comparing wildfire recovery at a bog and a fen along a burn severity gradient
(University of Waterloo, 2024-09-19) Wegener, Emma
Wildfires are increasing in intensity and severity, emitting carbon (C) stored in soil and biomass to the atmosphere. This is of increased importance in peatlands which have deep deposits of combustible soil. Carbon in peatlands has been accumulating for millennia, due to organic matter input exceeding decomposition and combustion. The presence of saturated soils inhibits the rapid oxidation of dead organic matter, thereby limiting C losses through decomposition. Carbon accumulation in peatlands is supported by the adaptations of characteristic vegetation assemblages, which can grow quickly and in high abundance, increasing the rate of C accumulation, or reducing rates of decay. As wildfires are becoming increasingly severe, collecting data over a range of burn severities, in an array of peatland types to better characterize rates of recovery is paramount. Thus, I measured C fluxes, plant functional traits, and plant community composition at a bog and a fen along a burn severity gradient, with the aim of gaining a better understanding of the influence of burn severity on recovery in different peatland types. I found that, six to seven years following wildfire, biomass accumulation was greater at the fen than the bog, especially the moderately burned fen with nearly 12-fold the biomass of the moderately burned bog; however, the plant community composition was dominated by opportunistic plants such as Betula glandulosa that were not characteristic of the unburned treatment. Plant functional traits suggested that response to disturbance differs among plant types along the burn severity gradient at each peatland type, where LDMC is regularly decreased along the burn severity gradient, and either SLA or height are increased. Understory GEP and ER are significantly greater at the fen than the bog, although NEE was not statistically different, as sequestration and efflux balance at each site to approximately 0 g C m-2 day-1. These results should be considered alongside tree and vegetation surveys, which suggest that while ground-level fluxes may be similar, overstory contributions to each site are crucial to consider as they contribute to the C storage capacity of the unburned sites, but are missed by ground-level fluxes. There is a great amount of C held in trees at the unburned sites, less at the moderately burned sites due to competition, and a high number of tree seedlings at the severely burned sites. Methane fluxes, however, appear to recover more slowly following deeper peat combustion, with moderate burns trending toward pre-burned conditions, while the severe burns have limited efflux of CH4, which may suggest that there has been a reduction in substrate quality or that the soil microbial community that has not yet recovered. The results of this study emphasize the need for more nuanced consideration of burn severity in peatland management and research. Severe burns are becoming more common with climate change, and implementation of burn severity into global C models is necessary to ensure accurate estimates of C losses from wildfire. This study also highlights the importance of distinguishing between bogs and fens in ecological modeling, as applying the same rates of C efflux or accumulation could lead to significant inaccuracies. Understanding these differences is crucial for prediction of C dynamics in peatland ecosystems, particularly in the context of increasing wildfire frequency and intensity.
Flocculation and ingress of cohesive solids in a mountainous gravel-bed river
(University of Waterloo, 2024-09-17) de Freitas Maltauro, Rafaela
Gravel-bed rivers draining mountainous headwater regions are critically important for the provision of high-quality drinking water and integrity in forested landscapes. These regions, however, have been increasingly impacted by natural (especially climate change-exacerbated) and anthropogenic landscape disturbances that can increase landscape connectivity and sediment delivery from hillslopes to receiving streams. Cohesive particles (<63 μm) increasingly mobilized during landscape disturbances are key vectors for nutrient and contaminant transport across the catchment continuum. Excess delivery of fine sediment mobilized from landscape disturbances can cause deleterious physical, chemical and biological impacts on streams by increasing turbidity, compromising habitats, ecological integrity, and challenging water treatability. However, processes controlling the propagation and storage of cohesive solids in gravel-bed rivers are still poorly understood. Given the complexity of flocculation and ingress processes under turbulent flow fields and the lack of reported rigorous field observations, most hydrodynamic fine sediment transport models disregard these processes, potentially leading to inaccurate model estimations. Accordingly, the main goal of this thesis was to evaluate the processes of flocculation and ingress, and the effects of these processes on the propagation and storage of cohesive solids in a gravel-bed river through the integration of laboratory, field, and modelling approaches. Five chapters were developed to achieve this goal: Chapter 2 investigated the in-situ characteristics of suspended sediment by measuring effective particle size distributions (LISST 200x) at four different sites of the study river at a range of flow conditions; Chapter 3 evaluated methods to measure fine sediment ingress rates and directional mechanisms by deploying >250 sediment traps, consisting of triplicates of three designs of sediment traps; Chapter 4, using those sediment traps, evaluated the hydraulic (discharge, water depth, Froude number, bed shear stress, and stream power) and sedimentological (suspended sediment concentration by mass and by volume) drivers of fine sediment ingress; Chapter 5, using a rotating annular flume, characterized the processes of suspended sediment transport over different bed configurations through deposition, ingress, and erosion experiments, and; Chapter 6 calibrated and validated a semi-empirical cohesive sediment transport model (RIVFLOC) using results from the rotating annular flume, and applied the model to the observed field conditions to better understand the transport and fate of these particles in the study river. Particles <500 μm in the Crowsnest River were predominantly transported in flocculated form. While the highest observed flow energy limited the development of larger flocs due to the breakage of bigger and more loosely attached flocs, microflocs were invariably observed, and their formation correlated positively with flow energy. The characterization of effective particle sizes between ingressed and suspended sediments demonstrated that, although the particle size distributions had similar modalities for both sediment types, ingressed sediment was coarser than suspended particles – demonstrating that interstitial flocculation can occur, even though it is also likely that coarser flocs are preferentially ingressed in the channel. Field measurements of ingress demonstrated that, for flocculated particles, ingress was predominantly vertical during higher energy flows, while horizontal mechanisms of accumulation were more important during lower energy flow conditions. The model application estimated that ~60 % of the upstream suspended sediment gets trapped in the channel framework over the ~10 km study reach. Although we lack independent means to validate these findings in the field, given the nearly continuous sediment supply from diffuse sources along the catchment, the fine sediment ingress rate recorded in an annular flume was well within the range of ingress rates measured in the field, which supports the validity of the modelled estimates. Despite high accumulation rates, field observations demonstrated that no sites were saturated or clogged with fine sediments during the field campaigns. The observations reported in this study bring some novel perspectives to the understanding of flocculation and ingress processes of cohesive solids in a gravel-bed river (i.e., in-situ flocculation mechanisms of suspended and ingressed particles, floc size effects on the ingress process, and the modelling framework of the propagation and storage of cohesive particles). The reported results also indicate the potential for future investigations on the role of the interstitial load for fine sediment storage and possible exfiltration mechanisms driven by groundwater upwelling. Given the importance of cohesive sediment as a vector for contaminant and nutrient transport and the limited capacity for interstitial flushing of fines, gravel-bed rivers may delay the downstream impacts of upstream disturbances (legacy effects) for decades. Accordingly, due to the increasingly reported deleterious impacts of excess cohesive sediment in gravel-bed streams, advancing knowledge on the propagation and storage of fine sediment, as proposed in this study, is imperative for its strategic management and prevention.
Using GeoAI and Mixed-Data to Classify Built Heritage
(University of Waterloo, 2024-09-04) Li, Siyu
Built heritage, which comprises structures that are valued for their historical or architectural characteristics, is important to community’s identity, sense of place, and, in many cases, economy. Many communities in Ontario have used Heritage Act provisions to protect locally significant buildings through local heritage registers or local bylaws that officially designate them as heritage structures. Recent changes introduced by Ontario’s Bill 23, the 2022 More Homes Built Faster Act, have significantly altered the heritage designation process by limiting how long a property can remain on a local heritage register. This change highlights the need for a more efficient method for municipalities to identify and classify potential heritage properties. Geospatial Artificial Intelligence (GeoAI), an innovative approach integrating AI with Geographic Information Science (GIS), has potential to automate heritage identification and classification tasks, and assist heritage planners. This thesis explores the potential of GeoAI to streamline heritage property identification and designation through three main models. These models leverage Convolutional Neural Networks (CNN) and Multi-Layer Perceptrons (MLP) to classify architectural styles, identify potential heritage properties, and predict heritage designations. The models were trained on non-spatial and geospatial datasets, including archival photographs and region-specific data from Ontario, enhancing their ability to detect architectural details and heritage features unique to the area. The results demonstrate the effectiveness of these models, with the Architectural Style Classification Model achieving a 89% accuracy, despite challenges with similar styles. The Heritage Identification Model significantly improved efficiency with a 96.62% accuracy rate, while the Heritage Property Designation Prediction Model, combining CNN and MLP approaches, achieved 96% accuracy. The findings highlight the potential of AI and GeoAI to aid heritage practices with new technological methods. This research contributes to the broader knowledge base by providing refined tools for decision-making in heritage conservation and also suggests directions for future research to further optimize the integration of GeoAI in heritage tasks.
After the Surge: Tourism as a Disaster Recovery Strategy in Tacloban, the Philippines
(University of Waterloo, 2024-09-04) Mohni, Celina
This thesis presents a comprehensive examination of the role of tourism in disaster recovery, specifically focusing on Tacloban’s response to Typhoon Yolanda in 2013. Employing case study methodology, this study delves into the dynamics of tourism development post-disaster, highlighting both organic growth and structured initiatives facilitated by local government and tourism bodies. The findings reveal that the influx of aid workers and disaster tourists played a pivotal role in the economic resurgence of Tacloban, transforming the city into a tourist attraction itself as well as a regional gateway for tourism. This unexpected shift not only bolstered immediate post-disaster economic stability but also laid the groundwork for sustainable economic development. The thesis underscores the dual role of tourism in providing immediate economic relief and fostering long-term economic growth, facilitated by strategic planning and policy-making. Key recommendations from the study emphasize the importance of preparedness in leveraging tourism for disaster recovery, suggesting the implementation of strategic frameworks to manage and maximize the benefits of tourism post-disaster. The research contributes to the broader discourse on disaster recovery and tourism, advocating for further studies to explore the potential of tourism in diverse post-disaster settings globally.
From the Ashes: How Tourism Became the Phoenix of Disaster Recovery A Case Study from Mount Merapi, Indonesia
(University of Waterloo, 2024-08-30) Palmer, Beth
This is a case study based on Mount Merapi, located on the border of both Central Java, and the Special Region of Yogyakarta, on Java, Indonesia. Merapi is one of the most active volcanoes in the world and in October of 2010, it begun one of its most eruptive sequences to date. Over 350 fatalities ensued and the destruction of hectares of agricultural lands, including thousands of homes. Due to the embedded cultural ideology of the communities in the Merapi region, a sense of unity and togetherness exuded across village borders, displaying community cohesion and social capital that laid the foundation for a synergized road to recovery. Tourism became a lifeline, propping up local communities supporting the transition from disaster to recovery. Tourism affected every aspect of residents' lives, working to fill the gaps left by traditional methods of disaster recovery. This study analyzes the resurgence of an innovative tourism industry in a post- disaster setting on Mount Merapi, Indonesia and the social/cultural capital and community cohesion that led to its success.
Leaving and moving on from the corporatized workplace: An emotional and feminist economic geography of tension and conflict at work
(University of Waterloo, 2024-08-27) Braithwaite, Alison
Employers have a vested interest in understanding why people leave. Feminist economic geographers have extensively researched the culture of the corporatized workplace, though they have rarely explored why people leave. This research examines the stories of people who left the corporatized workplace to start businesses oriented to positive social and/or environmental change. It explores what these stories can tell us about (i) the culture of the corporatized workplace, (ii) why people leave, and (iii) the pathways to starting a business oriented to positive change. Rather than looking at the workplace through the lens of identity, this research examines the workplace through the lens of care and affect theory. This research applies qualitative research design principles and uses narrative inquiry to collect partial life histories focused on why people leave the corporatized workplaces to start businesses oriented to positive social and/or environmental change. I did not provide criteria for what constituted businesses oriented to positive social and/or environmental change in any recruitment information. Participants were left to self-select into the study based on their own assessment of their business. I conducted 26 unstructured interviews where participants were asked to share experiences of three places: (i) the corporatized workplace, (ii) the liminal between leaving the corporatized workplace and starting their own business, and (iii) the business they viewed as oriented to positive change. The research applies affect theory using the work of Sara Ahmed and Lauren Berlant as analytical tools. It also relies on Gibson-Graham’s work in creating alternative economies. The research addresses why people leave the corporatized workplace at two scales: i) the systemic and ii) the personal. It then addresses the movement from the corporatized workplace to the business that participants defined as a positive change business. Many described that movement as a journey. At the scale of the system, the research identifies how the gameboard (the structure and ethos of the workplace), the Kool-Aid (the stated culture of the workplace), and the game (the lived culture of the workplace) press against those that care creating a care ceiling. A care ceiling is an invisible barrier to professional advancement for those who embody ethics of care. At the scale of the individual, I applied Ahmed’s definition of emotions to determine what was pressing against the participants, causing them to leave the corporatized workplace. The main factors in their leaving are (i) the manufactured urgency of the corporatized workplace that causes participants to behave in ways that are contrary to their values and (ii) value conflicts that occur with others in their workplaces. Those value conflicts cause slow wounding in the form of moral injury, which causes many participants to feel alienated and ultimately to leave the workplace. Many leave feeling burnt out, like they have lost pieces of themselves. The liminal is a journey of what bell hooks refers to as “remembering myself” and is driven by curiosity. It involves encounters that open possibilities, finding belonging, exploring Gibson-Graham’s (2006) “other possible worlds” (p. xii), and creating reparative stories. For those that complete the journey, it ends in a different way of being, where participants embrace species being, which can be defined as a place of owning themselves. The journey parallels the process used by Gibson-Graham to guide communities to alternative economies. This research contributes to the literature of economic geography, particularly feminist economic geography, including research on workplace culture and reparative approaches. It applies Marxist concepts of alienation and species being to the modern workplace. It also contributes to human resource management literature on why people leave their workplaces. Finally, it contributes to our societal understanding of how the culture of the corporatized workplace is reproduced, how challenging it is to transform, and provides insight into what people in the corporatized workplace are being asked to “lean into,” a neoliberal and individualistic framing popularized by Facebook (now Meta) former COO Sheryl Sandberg.
Examining the Ecosystem Evolution of Nikanotee Fen Watershed: An Ecohydrological Perspective
(University of Waterloo, 2024-07-10) Popovic, Natasa
Recognition of the environmental ramifications of long-term natural resource development in the Athabasca Oil Sands Region (AOSR) has prompted the implementation of sustainable land use practices. This includes obligatory regulations that require impacted landscapes to be returned to their pre-disturbance functionality. Ecosystem function (e.g., carbon sequestration) is driven by soil-plant-atmosphere exchanges of energy, carbon and water resources. Given the magnitude of disturbance during surface mining (i.e., removal of vegetation and the subsurface) the reestablishment of ecosystem function requires extensive reclamation. This involves the complete reconstruction of surface and subsurface ecosystem components including the establishment of a hydrological regime. Thus, reclamation ultimately creates ‘new’ landscapes, often beginning with a bare ground phase followed by planting campaigns, and the eventual development of widespread plant communities. An understanding of ecohydrological processes throughout the different post-construction evolutionary phases is necessary to evaluate i) ecosystem function and trajectory and ii) reclamation design and success. As the natural, undisturbed landscape of the AOSR consists of hydrologically connected upland forests and fen peatlands, two pilot-scale watersheds incorporating these landscapes have been constructed to examine the viability and design of multi-landscape reclamation endeavours in the region. This thesis captures the evolving ecohydrological regime during the first seven years (2013 - 2019) post-construction at one of the novel, constructed watersheds in the region, Nikanotee Fen Watershed (NFW). Ecosystem function and evolution of both the fen and upland were quantified based on key ecohydrological indicators (net ecosystem exchange (NEE), evapotranspiration (ET) and water-use efficiency (WUE)) using a multi-scale (ecosystem and plant community), multi-method (remote sensing, eddy covariance, instantaneous chamber measurements) approach. Over the course of the study period, both landscapes exhibited significant biophysical evolution, from bare ground to fully vegetated ecosystems, resulting in physical (e.g., altered albedo, surface roughness and producing plant-mediated shading) and functional (e.g., transpiration and carbon sequestration) transformations. Initially, during bare ground conditions, surface-atmosphere exchanges were driven by abiotic factors (atmospheric and edaphic conditions) and controlled by soil water availability. In the fen, due to near-surface water table, high soil moisture content, surface ponding and the low albedo of wet, bare peat, most available energy was partitioned to latent heat and a high degree of decoupling between the surface-atmosphere was observed. During this time, surface evaporation rates were consistently high and comparable to open-water values in the region. Due to the lack of plant community, the fen was a source of CO2 and WUE was low and driven by high evaporative losses. In the upland, the exposed dry sand-loam cover soil resulted in higher albedo and equal partitioning between latent and sensible heat. The drier edaphic conditions resulted in limited evaporation, with only small increases in response to precipitation events. Moreover, these conditions resulted in net carbon losses and similar to the fen, limited WUE. Once plant community became established, edaphic controls decreased, and surface-atmosphere exchanges were driven by plant-mediated responses to atmospheric conditions. In the fen, as water availability remained high, latent heat continued to be the dominant energy flux, but a larger proportion of available energy was partitioned to sensible heat, particularly during drier periods. Widespread plant coverage and the establishment of a thick litter layer supressed surface evaporative losses and increased transpiration, resulting in lower ET rates compared to bare ground conditions and greater surface-atmosphere coupling. Coinciding with plant growth, the fen quickly evolved from a CO2 source to a sink by year three post-construction. Moreover, once fully vegetated, WUE remained relatively stable despite seasonal hydrometeorological variability. Here, stable WUE trends reflect well-developed rooting architecture of the plant community and a well-connected groundwater network between the two landscape units resulting in hydrological self-regulation sufficient to maintain adequate plant function during periods of water stress. In the upland, the growth and development of treed species resulted in a marked increase in latent heat flux, ET rates, CO2 uptake and WUE, with seasonal trends mirroring plant phenology. However, at the conclusion of this study the upland was still functioning as a minor CO2 source, but is expected to become a sink in the near future as trees continue to mature. Overall, an examination of ecohydrological processes and feedbacks during early development suggests the constructed system is evolving towards a functional, self-sustaining ecosystem that’s able to withstand periodic environmental stress. Furthermore, rates and seasonal trends of key ecohydrological indicators (ET, NEE, WUE) at the constructed watershed were comparable to those observed at surrounding natural and post-disturbance boreal landscapes providing further support of ecosystem function. Results from this study provide insight to early ecosystem function and trajectories and can be applied to future designs and planting prescriptions to improve long-term reclamation success.
Evaluation of Wind Flows and Turbulent Fluxes in Complex Terrain of Canadian Rockies
(University of Waterloo, 2024-05-28) Rohanizadegan, Mina
In mountains, the role of diurnal wind (i.e. valley, slope winds) due to differential heating, radiation and topography in controlling fluxes of heat and water vapour is not well understood. Since data in high mountain areas are limited, high resolution models can help resolve near-surface processes and their diurnal changes to use as an input to hydrological models for more accurate predictions of evapotranspirartion and future water resources. Improvements over recent years in the resolution of Numerical weather prediction (NWP) models and large-eddy-simulation (LES) have had made great progress on resolving the atmospheric boundary layer (ABL) and boundary layer processes over mountainous terrain. In this work, the Weather Research and Forecasting (WRF) model is used to simulate flow in LES mode over the complex terrain of the Fortress Mountain and Marmot Creek research basins (MCRB and FMRB, respectively), Kananaskis Valley,Canadian Rockies, Alberta in mid- and late summer. The days selected in this study allow for development of thermally-induced wind circulation and ABL processes. However, the use of terrain-following coordinates in most numerical weather prediction models results in errors that propagate through the domain and can result in numerical instability. To avoid this issue when simulating flow over steep terrain a local smoothing approach was used, where smoothing is applied only where slope exceeds some predetermined threshold. The results are compared with global smoothing, which uniformly filters terrain, and is already implemented in WRF. Local smoothing with the cumulus parametrization activated only for the parent domain provides better predictions for surface wind direction, improved predictions for net radiation, and better RMSE for humidity, and was used for the rest of the analysis on turbulence kinetic energy (TKE) and near- surface processes. The model shows that valley flows are impacted by wind gusts and topographic wind originated from higher elevations blowing into the valley. In this study, up-valley flows were stronger in the wide but deeper Kananaskis Valley in MCRB, as compared to the narrower and shallower valley in FMRB. In addition, cold-air pools seem to linger longer in the deeper and wider valley at MCRB, but air temperature was lower in the early morning at the shallower but narrower valley at FMRB. The removal of the cold air pool due to temperature rise happened earlier in the valley in FMRB than in the valley of MCRB due to an elevated inversion layer of the deeper valley. Boundary layer processes and turbulence in complex terrain are influenced by thermally-induced flows, as well as dynamical or non-local winds. Data from three high-frequency eddy covariance systems at a northwest-facing slope location, and at two ridgetops at the south and north valley side walls of the Fortress Valley were combined with LES to investigate the influence of diurnal mountain flows on TKE. Simulated cross sections showed up-valley flow was inclined toward the northern valley wall at the southeast side of the valley, and the interactions between the up-valley flow and the cross-ridge flows contribute to TKE in the valley. It was found that there is a strong correlation between TKE and wind speed at ridgetops, while TKE in the valley correlated strongly with the wind speed at the northern ridgetop. Furthermore, TKE budget analysis showed that horizontal shear could be an important source of TKE production at the northwest-facing slope station in the Fortress Valley. The variability observed in TKE budget components across different locations within this high mountain basin indicates the significance of both horizontal and vertical exchange processes in the mechanisms governing TKE production. The final portion of this study evaluated model predictions of sensible and latent heat fluxes versus observations at three eddy-covariance locations in the Fortress Valley. The differences between model predictions and observations illustrates the crucial role of soil moisture, along with net radiation, in controlling the heat and evaporative fluxes in mountainous terrain. The observations over July and August were further used to quantify the variability of the sensible and latent fluxes with soil moisture content and net radiation, as influenced by elevation and vegetation. Observations showed that despite variations in vegetation type and elevation, the latent heat flux exhibited a weak correlation with soil moisture at each site but displayed a strong correlation with net radiation at all sites for both wet and dry days. But when all study sites were compared together for mid- versus late summer sunny days, it was noted that the local topography and soil moisture, radiation, and local flows can all have important impacts on turbulent fluxes. The findings also indicate that longer term data with a wider range of soil moisture, and topographical features (i.e slopes, aspect) will be beneficial for more in depth future studies on exchange processes in mountainous terrains.
Watershed Classification in the Great Lakes Basin: Implications for Water Quality and Agricultural Management Practices
(University of Waterloo, 2024-05-28) Hassan, Amina
In recent years, the Great Lakes have faced a resurgence of cyanobacterial harmful algae blooms (cHAB), primarily attributed to non-point sources, notably agricultural activities. While significant efforts have been directed toward implementing conservation practices to mitigate nutrient losses, existing literature often examines the efficacy of best management practices (BMPs) and spatiotemporal drivers of nutrient loss separately, neglecting their interconnectedness. Recent studies suggest that conservation practices' effectiveness may vary spatially, necessitating targeted interventions to avoid trade-offs. This study aims to delineate distinct ecoregions based on known spatiotemporal drivers of nutrient loss and analyze their implications for water quality across different land use-land cover (LULC) types. Using Google Earth Engine (GEE), two Cascade K-means clustering analyses were conducted separately on climate and geophysical variables, resulting in three distinct ecoregions for each domain. These findings were integrated with data from the Provincial Water Quality Monitoring Network (PWQMN) and HYDAT stations to assess patterns in water quality degradation and nutrient loss mechanisms across ecoregions. Additionally, statistically downscaled climate change datasets from Environment and Climate Change Canada (ECCC) were utilized to determine shifts in climate conditions across established climate ecoregions. Furthermore, climatic ecoregions displayed a latitude-dependent pattern in water quality degradation. Under projected climate changes, the coolest regions are anticipated to resemble current conditions in the warmest regions, leading to a northward shift in agricultural suitability. These findings underscore the necessity of adopting a context-dependent approach to agricultural management practices, especially in light of projected climate shifts. A one-size-fits-all approach to BMP recommendations and implementation falls short, highlighting the importance of tailored strategies to address the unique challenges posed by each ecoregion.
The water and energy balance of Lake Miwasin: a pilot-scale oil sands pit lake
(University of Waterloo, 2024-05-21) Zabel, Austin
Energy companies in the Athabasca Oil Sands Region in Alberta, Canada are studying the viability of incorporating pit lakes into reclamation closure designs to both sequester tailings and re-integrate the mining lease into the broader natural landscape. Lake Miwasin is a pilot-scale oil sands pit lake encompassed by a constructed catchment where the volume of the water cap is not actively managed. This research quantified the water and energy balances of Lake Miwasin during the open water season for two consecutive years. As the constructed catchment lacks both natural waterbodies and connectivity to a legacy groundwater system, freshwater additions to the lake during the summer season were governed by rainfall. Above average rainfall during the first year triggered surface water inflow events that diluted the over-winter water volume by ~ 25%. The second year had below average rainfall resulting in minimal surface water inflow and a 30 cm drop in lake stage. The lake became thermally stratified during the open water season absorbing high amounts of energy in the spring and releasing this energy in late summer/fall. Despite being constructed at a pilot-scale, the timing and magnitude of the maximum heat content were comparable to small natural waterbodies. The small fetch and surrounding landscape features led to a sheltering effect reducing wind action at the surface contributing to lower correlations between climatic variables and the surface energy fluxes compared to larger neighboring lakes. This research indicates variable climatic conditions, lake size, and surrounding landscape features will influence the water balance and energetics of future oil sands pit lakes. Consideration of the presented results and continued research is required to guide the implementation of these contemporary landscape features throughout the Athabasca Oil Sands Region.
Enhancing Open Government Data Quality: A Quantitative Evaluation Assessment for Cross- Jurisdictional Open Data Programs in Waterloo Region
(University of Waterloo, 2024-05-06) Li, Xuxuan
This study builds on the previous research for identifying the current issues and gaps existing for the cross-jurisdictional data quality of the open data programs in the Waterloo region, not only as the governments in the Waterloo region have a unique two-tier municipalities structure, but also how the four municipalities the City of Waterloo, the City of Kitchener, the City of Cambridge and the Region of Waterloo shares one same data portal. The goals of this study are to understand what data quality metrics are important for the quality of open data, and how an evaluation tool can be created to effectively measure the data quality for the open data in the Region of Waterloo. A quantitative approach was used for measuring individual metrics of the data quality dimensions such as completeness, timeliness, metadata, and usability. The results show there are still a lot of improvements that can be made by the lower-tier municipalities on quality assurance, regular maintenance, and updates of data policies. The results also indicated that upper-tier municipalities like the regional government of Waterloo can take the leading role in improving the overall data quality of open data programs by creating open metadata and data standards. Additionally, the results also note the insufficient of both current and previous research and provide suggestions for future studies in similar settings.
Advancements in Road Lane Mapping: Comparative Analysis of Deep Learning-based Semantic Segmentation Methods Using Aerial Imagery
(University of Waterloo, 2024-05-01) Liu, Xuanchen (Willow)
The rapid advancement of autonomous vehicles (AVs) underscores the necessity for high-definition (HD) maps, with road lane information being crucial for their navigation. The widespread use of Earth observation data, including aerial imagery, provides invaluable resources for constructing these maps. However, to fully exploit the potential of aerial imagery for HD road map creation, it is essential to leverage the capabilities of artificial intelligence (AI) and deep learning technologies. Conversely, the domain of remote sensing has not yet fully explored the development of specialized models for road lane extraction, an area where the field of computer vision has made significant progress with the introduction of advanced semantic segmentation models. This research undertakes a comprehensive comparative analysis of twelve deep learning-based semantic segmentation models, specifically to measure their skill in road lane marking extraction, with a special emphasis on a novel dataset characterized by partially labeled instances. This investigation aims to examine the models' performance when applied to scenarios with minimal labeled data, examining their efficiency, accuracy, and ability to adapt under conditions of limited annotation and transfer learning. The outcome of this study highlights the distinct advantage of Transformer-based models over their Convolutional Neural Network (CNN) counterparts in the context of extracting road lanes from aerial imagery. Remarkably, within the state-of-the-art models, such as Segmenting Transformers (SegFormer), Shifted Window (Swin) Transformer, and Twins Scaled Vision Transformer (Twins-SVT) exhibit superior performance. The empirical results on the Waterloo Urban Scene dataset mark substantial progress, with mean Intersection over Union (IoU) scores ranging from 33.56% to 76.11%, precision from 64.33% to 77.44%, recall from 66.0% to 98.96%, and F1 scores from 44.34% to 85.35%. These findings underscore the benefits of model pretraining and the distinctive attributes of the dataset in strengthening the effectiveness of models for HD road map development, announcing new possibilities in the advancement of autonomous vehicle navigation systems.
An Evaluation of the Impact of Seasonal Land Cover Change on Evapotranspiration Estimates at the Catchment Scale in the Upper Gundar River Basin, Tamil Nadu, India
(University of Waterloo, 2024-04-24) Senthilkumaran, Akash
Changes in the water cycle influence the energy balance of the Earth. The water cycle is represented using the water balance equation, in which Evapotranspiration (ET) is a vital parameter. One of the main drivers of the change in ET within a specific area is the change in land cover. This study focuses on estimating ET across the Upper Gundar River Basin located in the state of Tamil Nadu, India. Notable features of this landscape include agriculture throughout the year supported using an extensive network of tanks and borewells, and the presence of Prosopis juliflora, a widely prevalent invasive species known to consume groundwater and moisture. Due to the lack of spatial variability in point ET measurements, ET models using remote sensing imagery as the main forcing data have been widely used to assess the spatial variability and temporal variability based on the principle of surface energy balance. These models are collectively referred to as Surface Energy Balance (SEB) models. The model used in our study is the Surface Energy Balance Algorithm for Land (SEBAL) model to estimate ET for two periods of the year, indicating mid-summer and the end of the northeast monsoon for the years 2006, 2014 and 2021. Since land cover changes drive ET, land cover classification and seasonal change detection are also performed for the same time periods. Imagery from Landsat satellites is used, and one image is chosen to represent the specific season. The major land cover classes chosen in our study are water, pre-growth, agriculture, Prosopis juliflora (prosopis), barren land, and exposed soil. Along with the Landsat imagery, to run SEBAL, Aster DEM is used along with in-situ weather data and GLDAS data. Over 90% levels of overall accuracy were achieved for all year-season combinations for the land cover classification. Using SEBAL, Actual Evapotranspiration (ETa) for all the classes is calculated except the water classes. Due to the lack of in-situ measurements, an intermodal comparison was performed with the EEFlux product available at the same resolution derived using the METRIC algorithm using land cover classes as units of comparison. The comparisons are carried out using correlation coefficient (r), root mean squared error (RMSE), and mean values. Highest mean values were observed for either the agriculture or prosopis class, and the lowest mean value was exhibited by the exposed soil class on all occasions. Within all summers, considering all the years, the average correlation coefficient and RMSE were 0.8, 1.2 mm/day, and for monsoon, the averages were 0.5 and 0.85 mm/day, indicating increased proximity during the monsoon season between SEBAL and EEFlux. Similarly, the range of mean values between classes in summer is 2.12 mm/day, 1.36 mm/day in the monsoon. In terms of the energy fluxes used to determine ETa, a decrease in monsoon is observed for soil heat flux (G), instantaneous net radiant energy (Rn_inst), and net radiation in a day (Rn_24). For sensible heat flux (H), classes with vegetation tend to have lower values in comparison to the classes without vegetation. Finally, average water outflux is calculated encompassing all classes by multiplying the area of a class with mean ETa, and the values observed in summer and monsoon alternatively for the years 2006, 2014, and 2021 in m3/day are 5,142,212, 3,534,906, 2,954,897, 4,046,322, 5,369,191, 4,512,596.
Assessment of Drivers of Algal Biomass in North American Great Lakes via Satellite Remote Sensing
(University of Waterloo, 2024-04-02) Dallosch, Michael
Lakes are regarded as sentinels of change, where shifts in environmental conditions significantly affect lake phenology. A significant consequence of the change is the perceived increase in the frequency, magnitude, and severity of algal blooms in lakes globally. Algal blooms/increased productivity in lakes pose significant ecological, economic and health risks, impacting fisheries, tourism, and freshwater access. The impacts of external nutrient loading from anthropogenic sources are well documented; however, blooms have been observed to occur in even remote lakes. Climate change is a hypothesized driver of these recent algal bloom trends, such as increasing global air temperatures, water temperatures, lake ice loss, precipitation intensity, and drought. Past research on the impact of climatic drivers on algal biomass dynamics has often been limited to lab, mesocosm, or short termed observations, due to limited in situ data. New remote sensing data products make use of historic multispectral satellite image archives to provide greater spatial and temporal coverage of algal biomass concentrations, allowing for longer time series observational studies to be conducted over large areas. Using data provided by the European Space Agency (ESA) Climate Change Initiative (CCI) Lakes project (product version 2.0.0), daily chlorophyll-a (chl-a; proxy of algal biomass), Lake Surface Water Temperature (LSWT) and Lake Ice Cover (LIC) from 2002 to 2020 were derived from five North American Great Lakes: Great Bear Lake (GBL), Great Slave Lake (GSL), Lake Athabasca (LA), Lake Winnipeg (LW), and Lake Erie (LE). Additional atmospheric and lake physical variables were provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5-Land data as part of the ERA5 climate reanalysis product including: 2-m air temperature (T2m), Total Precipitation (PPT), Surface Net Solar Radiation (SNSR), Surface Runoff (SR) and Subsurface Runoff (SSR), Wind Speed (WS) and Lake Mix-Layer Depth (LMLD). Such data products allow for comprehensive time series analysis on the interaction effects of atmospheric and lake physical parameters on algal biomass dynamics. Winter temperatures exhibit the highest rate of change relative to other seasons, where LIC loss is important for Northern hemisphere lakes; however, its effect on algal biomass dynamics is relatively unknown. To investigate how LIC duration alters algal biomass in North American Great Lakes, annual and seasonal algal biomass, LSWT and LIC parameters were calculated for the five study lakes using ESA CCI Lakes data. Algal biomasses (β = 0.01 – 0.75 μg L-1 yr-1) and LSWT (β = 0.03 – 0.14 K yr-1) were found to increase, with a general decrease in LIC (β = -0.88 – -1.08 Days yr-1) from 2002 to 2020. Vector autoregressions (VARs) showed that in Northern Lakes (NL; GBL, GSL and LA), LSWT and LIC parameters provide greater explanatory power for annual/seasonal chl-a concentrations (median adj. r2 = 0.75) compared to Southern Lakes (median adj. r2 = 0.46). Additionally, LIC parameters were found to provide higher explanatory power for NLs during the spring season compared to LSWT. However, higher explanatory power does not indicate predictive capacity, where machine learning methods may provide stronger predictive models. To determine if LIC may act as a predictor of algal biomass parameters, multiple linear regression (MLR) and artificial neural networks (ANN) were constructed using per-pixel observations of annual/seasonal algal biomass, LSWT, and LIC parameters. Irrespective of season, LSWT only models returned lower prediction error (median NRMSE = 0.82) compared to LIC only models (median NRMSE = 0.93). However, models consisting of both LIC and LSWT returned the lowest predictive error (median NRMSE = 0.75). While LIC did not act as a strong predictor of algal biomass, a random forest (RF) classifier was used to determine whether LIC could classify the presence of lake-specific anomalies in chl-a concentrations. The RF model found that LIC parameters (ice on/off) had the highest mean accuracy decrease on average for NLs during the spring season. LIC timings are changing, where it was found to have greater importance on springtime abnormal algal biomass growth in NLs. While LIC was important at this time compared to LSWT, the impact of other important atmospheric and lake physical variables on algal biomass dynamics are not well understood, particularly at a smaller temporal scale (i.e., daily). To assess the potential interaction effects between algal biomass, atmospheric, and lake physical parameters, a network analysis was conducted using a High Order Dynamic Gaussian Bayesian Network (HO-DGBN) for the original time series, the stationary, non-stationary, and residual signals at varying temporal ranges (Δ: daily, three days, weekly, biweekly, and monthly averages). It was found that LSWT, T2m and SNSR were the most important parameters on average, where LSWT exhibited the highest importance on the daily scale compared to the monthly. Additionally, LMLD returned increased importance at longer temporal frequencies, while SSR returned increased importance at shorter temporal frequencies. Temperature interactions were mixed, typically returning both positive and negative interactions, while SNSR typically exhibited a positive interaction with chl-a, while LMLD exhibited a frequent negative interaction. PPT and WS were found to be the least important parameters in all study lakes. This thesis provides some of the first analytical uses of the ESA CCI Lakes product; a product that undergoes regular updates (every two years or so) as new satellite and in situ data become available, and algorithms for the retrieval of chl-a, LSWT and LIC are being improved. As such, improvements are expected in future releases of the product, limiting the accuracy of some findings in the thesis. Of the data presented, there is evidence that LIC is a significant contributor to spring algal biomass dynamics for NLs; however, Southern Lakes (SL; LW and LE) exhibit more complex interactions, likely due to anthropogenic impacts. This thesis identifies the complexity of LSWT interactions with algal biomass and identifies LMLD as a predominantly negative effect in the development of algal biomass. Algal biomasses are increasing, where increases in LSWT yield higher algal biomass peaks (at varying times throughout the year) within the study lakes. Future climate scenarios may provide conditions favorable for algal biomass growth, where Northern landscapes are at the greatest risk.
Methane Cycling in Northern Peatlands Following Wildfire
(University of Waterloo, 2024-03-26) Shingler, Abigail
Peatlands are an important component of the global carbon (C) cycle, they operate as long-term global sinks of atmospheric carbon dioxide (CO2) and sources of methane (CH4). However, they are becoming increasingly vulnerable to disturbances such as wildfire. Understanding the impact of wildfire on greenhouse gas dynamics is important as the frequency and severity of these fires continues to increase. Loss of labile substrate and methanogenic community is often attributed as the driver behind CO2 and CH4 emission reductions from peatland soils post-wildfire. Soil incubations were conducted using samples from both burned and unburned peatlands immediately (Alberta) and 2-years (Ontario) post fire to measure and compare CH4 production potential and oxidation. In-situ CH4 and CO2 flux measurements were conducted at the Alberta site immediately after fire. Environmental variables such as water table depth, soil temperature and moisture were collected at each site. Soil samples from the Ontario site were also analyzed for phenolic compounds, pH, and electric conductivity. In both the recently burned and 2-year post fire incubations, lower CH4 prodution was observed at the burned sites. In-situ field fluxes determined that both ecosystem respiration (ER) and net ecosystem exchange (NEE) was lower and CH4 flux indicated net CH4 uptake at the burned site compared to the natural site, immediately post-fire. Overall, this study enhances our understanding of the impacts of wildfire on greenhouse gas dynamics and carbon storage in peatland ecosystems both immediately and 2-years post-burn. This understanding is important for the establishment of peatland carbon budgets in response to climate change, contributing to the development of accurate and reliable global carbon budgets and climate modelling that can account for the increasing vulnerability of boreal peatlands to fire.
First Nation land and well-being: Exploring the relationship of First Nation land management systems with community well-being, informality within land management, and the development of an agent-based First Nation land-use voting model for experiments on policy adoption at Curve Lake First Nation
(University of Waterloo, 2024-03-15) Fligg, Robert
Land management is a pressing issue for reconciling and reconnecting First Nations with their land. Many First Nations have taken more control and responsibility over the management of their land that is key to their well-being. Currently, two legislative pathways (e.g., the First Nation Land Management (FNLM) regime and frameworks of self-government) provide more control by First Nations over their land outside of the Indian Act, however, there are gaps in societies’ understanding about the relationship of First Nation land management (in the broader sense) and their well-being. The overarching goal of the dissertation, seeks to improve societies’ understanding about the relationship between First Nation land management (broadly defined, including land management systems, property rights systems, land-use policies and planning) and First Nation well-being. Chapter 2 contributes by asking the question: “does the land-management regime of a First Nation correlate with differing levels of community well-being among First Nations as measured using the community well-being (CWB) index?”. It also investigates if there have been temporal effects by asking the question: “do First Nation communities experience different CWB trajectories when under a particular land management regime when they transition from one land management regime to another?” First Nation communities that have more control over managing their land have on average higher CWB scores, however, a community under any land management regime (e.g., under the Indian Act, or sub-set of the Indian Act ‘Reserve Land and Environment Management Program’ (RLEMP), Framework Agreement on First Nation Land Management Act (formerly First Nations Land Management Act (FNLM)) or a framework of self-government) could achieve a high CWB score (e.g., above the non-Indigenous average) depending on key economic factors (e.g., location of a community to an economic area). Regardless of CWB scores a land management regime is crucial to First Nation cultural well-being that may include pathways or mechanisms to develop formal community objectives and policies on land-use practices (e.g., on land relationships and stewardship). Building on Chapter 2, Chapter 3 looks deeper into First Nation land management, land-use practices, policy and planning, and property rights through collaboration with Curve Lake First Nation. Chapter 3 investigates by First Nation member-type (i.e., land holder vs non-land holder, and ‘on’ vs ‘off-reserve’ members) land management knowledge, and the impact member type has on land management and land-use practices. To achieve the objective of Chapter 3, a social survey was created in collaboration with Curve Lake First Nation to investigate formal and informal land-use practices and policy in land management, and whether there was a gap between members “wants and needs” regarding what should happen according to (formal) policy or process and what actually happens on the ground (informal). Although results from Chapter 3 found a correlation of land holder/non-land holder disconnect with uncertainty regarding policy on land use-practices that suggested a need for formal land-use policy and planning, the results also suggested CP holders and non-CP holders agreed that all parcels should be managed and used according to community values. Chapter 4 takes a step toward filling the gap in societies’ understanding by utilizing the knowledge and data from Chapters 2 and 3 in the development of a First Nation land-use voting model to investigate how formal land use policy on individual support for land policy and community land objectives could be conceptualized as a collective well-being. Chapter 4 investigated the objective by asking research questions on “how different member-levels of propensity for land information knowledge, ambition, stewardship, and how they collaborate affect formal land-use plan and potential land-policy adoption”, and secondly “how relationships and changes in members’ knowledge and attitudes affect support of formal land-use policy and its potential adoption?” Responses to the Curve Lake First Nation social survey was further coded for member responses on land related questions about their community, and outside community, on systems of land management, property rights, land-use policy and planning, and opinions on well-being that could be used to empirically inform an agent-based model called the ‘First Nation Land-Use Voting Model’. Model results suggest with greater support for community specific objectives for a balance in socio-economic and cultural well-being, there is greater support for the adoption of formal land-use policy and planning.

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