▼ 

The unique characteristics of people with autism influence their spatial experience and interaction with the physical environment resulting in struggles not only to them but also to their families and caregivers. This research, which drew on the therapeutic landscapes theory, aimed at exploring these challenges in home environment and the role of modifying the physical home environment in alleviating these challenges. The research employed qualitative methods on three phases: a) learning from the experience of key informants who are involved in creating or modifying the home environment of people with autism. This phase involved interviews (n=4) with architects and interviews (n=2) and a focus group (n= 9 participants) with Occupational Therapists OTs) ; b) online survey across Canada and U.S.A with families of children with autism (n=168) , and; c) in-depth diary interviews with three selected case studies of families having children with autism and living in different housing typology (house, townhouse and apartment) in the Great Toronto Area. The identified themes provided comprehensive understanding on the following: (1) the common characteristics of people with autism affecting their interaction with the built environment; (2) the physical, social and psychological challenges that affect the quality of life of children with autism and their families in their home environment and the physical elements contributing to these challenges; (3) the common home modifications adapted by families to face these challenges; and; (4) the role of home modifications in shaping home environment as a therapeutic landscapes of healing. It was evident that the implemented modifications positively affected the families’ experiences of home as a physical, social, and; symbolic space.

Thesis

Master of Arts (MA)

Advisors/Committee Members: Geography and Earth Sciences.

▼ 

Employing an expanded meaning of the concept of sense of place within Health Geography, this thesis explores the relationship between sense of place and mental wellbeing of immigrants. The concept of sense of place demonstrates the importance of specific places for socioeconomic and health impacts on individuals and groups in their societies. While research has explored immigrants’ sense of place, few studies have attempted to explore visible minority’s perceptions of place and its influence on wellbeing. Using qualitative and quantitative techniques, this thesis explores the perceptions and experiences of place amongst Ghanaian and Somali immigrants in Hamilton, Ontario, Canada. First, we explore key informants’ revelations on immigrants’ sense of place and mental wellness in Hamilton, Ontario. Findings provide insight into the role of policies that affect determinants of health amongst immigrants. Second, we examine the effects of self-perceived mental wellness, socioeconomic and demographic variables on sense of place amongst Ghanaian and Somali immigrants living in Hamilton, based on an analysis of a survey questionnaire (n=236). Findings highlight a positive relationship between sense of place and mental wellness. Third, using descriptive and multivariate regression methods, we focus on factors that predict African immigrants’ life satisfaction in Canada. We examine sociodemographic, economic and health-related factors that predict life satisfaction amongst African immigrants, specifically Ghanaian and Somali immigrants. We find that immigrant settlement workers and agencies would be better able to meet the needs of immigrants if they are conscious of the factors that would empower immigrants to cope with life stresses. We suggest a reduction of stress by helping individuals and families identify sources of support, providing jobs, affordable housing, language interpretation and training. Lastly, we explore specific places, religious sites and their relationship to health and wellbeing for immigrants. Specifically, we explore churches and mosques where Ghanaian and Somali immigrants worship. We find that places of worship are significant for physical health, social, emotional, spiritual, mental, and general quality of life amongst immigrants. The thesis is highly relevant in the current Canadian policy context, which includes contribution to the understanding of the determinants of health and integration of immigrants, providing insights into the concepts of sense of place and mental wellbeing, and broadening our understanding of African immigrants’ integration. Overall, this thesis develops a better understanding of immigrants’ settlement and integration, and further contributes to the broader immigration literature.

Thesis

Doctor of Philosophy (PhD)

Employing an expanded meaning of the concept of sense of place within Health Geography, this thesis explores the relationship between sense of place and mental wellbeing of immigrants. The concept of sense of place demonstrates the importance of specific…

Advisors/Committee Members: NEWBOLD, BRUCE, Geography and Earth Sciences.

▼ The increasing length of the daily commute is a major issue for many commuters in the Greater Toronto and Hamilton Area (GTHA). In order to alleviate this problem through policy, the policy makers require more in-depth understanding of this issue. This study explores different travel behaviour, socioeconomic and labour market determinants of commuting distance for resident workers in the GTHA, especially those having normal commutes and those having extreme commutes. This study also explores which areas of the GTHA are most self-contained, and what are the average commuting distances of each sub-region of the GTHA. The primary data source for this study was Transportation Tomorrow Survey (TTS) for the year 2011. Supplementary data were obtained from InfoCanada and Statistics Canada. Descriptive analysis in this study, focused at the Census Sub-Division (CSD), examined self-containment, outbound commutes, inbound commutes, resident employees and jobs densities, and average commute distances for place of residence and place of work. Study results showed that Toronto and Hamilton CSDs are the most self-contained areas in the GTHA, whereas areas located in the north and northwest of Toronto are major sources of outgoing commutes. Toronto and its adjacent CSDs have the lowest average commuting distance, whereas residents of Georgina and Brock commute exceptionally long distances. Multivariate regression analyses were applied to a disaggregate dataset (TTS). Workers older than 15 years of age living in the GTHA were divided into two major categories based on the length of their commute: (i) normal commuters (those having a mean commuting distance of 10.8 km) and (ii) extreme commuters (those having a mean commuting distance of 40.9 km). Factors affecting commuting distance for these two groups were examined. Similarly, residents living and working in the GTHA were divided into two categories: Resident workers living in (i) Jobs-rich areas or (ii) Resident-rich areas. Factors affecting commuting distance of these resident workers were also examined. The key controlling factors of commuting distance include gender, age, mode of transportation, employment status, ratio of jobs to employed residents, age of youngest child, auto availability in household, multi-worker household, median income, jobs and population density, and distance from CBD. Significant socioeconomic, travel behaviour and land use determinants for normal commute distances were also applicable to extreme commute distance. Transit was the preferred mode of transportation for long distance commuters in the GTHA, except for those living in job-rich areas. Workers associated with Sales and Service occupation and living in jobs-rich areas exhibited shorter commute than those in General/Clerical occupation. These findings are important to understand the changing travel patterns and behaviours of commuters in the GTHA. These results will be of interest to transportation planners, engineers, and policy makers as it highlights the inclination of long distance… Advisors/Committee Members: Kanaroglou, Pavlos, Geography and Earth Sciences.

▼ 

The importance of citizen’s psychological need for community, amenities, and the feeling of equitable distribution of the varied impacts from urban change are gaining recognition as important factors in evaluating sustainable urban change. The inclusion of indicators that capture the equitable distribution of urban change impacts are a rare addition to the vast list of sustainability indicator sets available to researchers. Rarer still is the application of Integrated Urban Models (IUMs) and sustainability indicators in assessing the sustainability of land use and transportation policies which impact not only the form and structure of cities, but also the health and wellbeing of the city residents. Using three land use scenarios relevant to the study area: the City of Hamilton, scenarios which simulate alternative residential density patterns, the suburbanization of employment and the closure of elementary and secondary schools are projected into the medium term future using an integrated GIS-based model for simulating the consequences of demographic changes and population ageing on transportation (IMPACT), a sustainability indicator module and a set of indicators measuring the degree to which the urban change is just. The sustainability values generated from the use of IMPACT and SUSTAIN offer valuable insight to the literature related to each scenario. More importantly, the justice indicators add value information as to the impact of urban change on vulnerable population groups. The combination of IMPACT and SUSTAIN offers new avenue and method for future research on the sustainability of urban change.

Master of Arts (MA)

Advisors/Committee Members: Kanaroglou, Pavlos, Scott, Darren, Geography and Earth Sciences.

▼ 

This study explores telecommuter travel behaviour by examining discretionary travel distance and mode choice. The study utilizes data obtained from the 2005 origin-destination survey conducted by TRANS, a joint transportation planning committee serving the National Capital Region of Canada. The study compares and explains the discretionary travel behavior of teleworkers relative to other population groups and identifies that the average teleworker travels 3 times farther than regular workers and 1.7 times farther than non-workers for discretionary purposes. Regression indicates that dependent children, vehicle accessibility, housing type, residential distance to the urban core, land-use mix, residence within a Greenbelt region and day of the week all positively affect travel distance. Conversely, age, proximity to shopping centers and inclement weather demonstrate significant negative effects. Then, through binary logistic regression, the study confirms that work status significantly influences mode choice. Similarly, the following predictor variables demonstrate a significant positive effect towards active mode choice: teleworker work status, larger household size, greater income, warmer temperature, closer proximity to shopping centers, apartment housing type, trips for recreational and restaurant purposes, taking subsequent trips in a day, and travel between 8:00 A.M. and 4:00 P.M. On the contrary, increased entropy, trips within the Greenbelt region, dependent children under 16 years old, increased vehicle accessibility and trips for transporting someone or for shopping purposes all reduce the probability of active travel mode choice.

Master of Arts (MA)

Advisors/Committee Members: Scott, Darren M., Kanaroglou, Pavlos, Geography and Earth Sciences.

▼ 

Excess nutrients are currently impacting the ecosystem, fisheries, and recreational use of Lake Simcoe. The objective of this study was to determine the importance of groundwater as a pathway for nutrient input during base flow periods to a landfill impacted urban stream in Barrie, Ontario, which flows directly into the lake. A characterization of a 28 m reach was created using sediment and water level data, and a groundwater flux map of the stream was creating using heat tracer methods. This data was combined with the shallow groundwater nutrient concentration distribution measured with multi-level piezometers and diffusion samplers to calculate nutrient discharge. Such fine-scale measurements of nutrient discharge using groundwater-based data like these have not previously been reported. The water flux results were then extrapolated to a larger 460 reach (Site B) of Dyment’s Creek, and combined with groundwater contaminant data from that reach to derive a crude estimate of nutrient discharge at a larger scale. Groundwater soluble reactive phosphorus (SRP) and ammonium concentrations were much higher than stream concentrations. Estimates of total SRP discharge ranged from 3.6 to 8.1 g/d at Site A and 38 to 108 g/d at Site B, and ammonium discharge ranged from 66 to 218 g/d at Site A and 757 to 2043 g/d at Site B. This study showed that groundwater is an important pathway for nutrients to enter Dyment’s Creek, and this pathway that must be considered when addressing nutrient input to Lake Simcoe.

Master of Science (MSc)

Advisors/Committee Members: Smith, James, Roy, James, Geography and Earth Sciences.

▼ 

Sense of place (SoP) at the neighbourhood scale is one phenomenon that can bring to light the forces that shape residents’ experiences of living in urban neighbourhoods, and play a role in shaping their identity. At an even smaller scale are the gathering places of everyday life, where people can come together and spend time on a regular basis. This research is about single women’s experiences of local gathering places and their neighbourhood SoP in Hamilton, Ontario, from a feminist perspective. Feminist research values the knowledge and experiences of research participants and has the goal of understanding the world in order to build a more just society. A qualitative case study was employed, with face-to-face interviews (n=15) being the primary method of data collection. Participants were single mothers and single older women living in a neighbourhood in central-east, lower city Hamilton. This thesis explores the themes resulting from the interviews, including: factors influencing neighbourhood SoP; types of gathering places; social and emotional qualities of gathering places; physical/spatial qualities of gathering places, and; the relationship between gathering places and neighbourhood sense of place. These themes highlight the importance of gathering places to neighbourhood SoP, and the potential for the perspectives and recommendations of the participants to be included in current efforts around neighbourhood development in Hamilton. The results also point to areas for further research around SoP, and next steps for Hamilton in terms of creating a safe and age-friendly city, and engaging in critical community development.

Master of Arts (MA)

Advisors/Committee Members: Williams, Allison, Geography and Earth Sciences.

▼ 

Water-quality in freshwater ecosystems is linked to metal contaminant sequestration and transport by suspended aquatic floc. This doctoral thesis investigates the combined microscale biogeochemical processes as well as macroscale hydrodynamic mechanisms controlling trace metal dynamics of freshwater floc, through comparative assessments of floc versus bottom bed sediment metal(loid) (Ag, As, Co, Cu, Ni and Pb) sequestration/mobilization across aquatic ecosystems ranging in physico-chemistry (e.g. pH, organic carbon, Fe/trace metal concentrations) in the Boreal Forest Region of Ontario and under variable energy-regimes (i.e. calm, windy, prolonged-storm) in a shallow wave-dominated urban beach in Lake Ontario, Canada. The results establish differential biogeochemical controls in suspended floc versus bed sediments influencing the abundance, reactivity and type of Fe minerals affecting trace metal abundance and solid-phase partitioning patterns between these two compartments. Specifically, this work demonstrates a microbial underpinning to floc collection of amorphous Fe oxyhydroxides (FeOOH) controlling floc metal sorption, retention and overall metal concentrations that are significantly greater in suspended floc than bed sediment. In contrast, crystalline Fe oxides (FeOx) dominate sediment metal retention, due to reductive dissolution and/or mineral aging of FeOOH, where sediment solid-solution metal partitioning is more influenced by system physico-chemistry (i.e pH). Further, rapid fluctuations in energy regime influencing re-suspension/settling of floc and sediment (i.e. surficial fine-grained lamina (SFGL) versus underlying consolidated sediments) result in temporal and spatial hydrodynamic-dependent mixing of Fe mineral phases, altering metal abundance and solid-phase metal partitioning in each compartment. Collectively, findings of this innovative integrated thesis work provide new understanding of the physical and biogeochemical controls on Fe cycling/mineral transformations between floc and bed sediments, ultimately affecting trace metal iv behaviour between these compartments and fate in freshwater environments. This insight has important implications for policy development in improving risk management of aquatic systems under varying physico-chemical and hydrodynamic conditions.

Doctor of Philosophy (PhD)

Advisors/Committee Members: Warren, Lesley A, Geography and Earth Sciences.

▼ 

Modern microbialites provide the opportunity to explore the influences of biology on microbialite formation and understand how biosignatures can be preserved in these structures. In this study, we used the isotopic compositions (δ¹³C) of phospholipid fatty acids (PLFAs) and their structurally-defined profiles, in conjunction with calcium carbonate isotopic compositions and imaging to evaluate microbial autotrophic and heterotrophic processes associated with freshwater microbialites from Kelly Lake, British Columbia. This was done to determine what types of metabolism may have been influencing microbialite growth and whether a biosignature of this process was preserved. In addition, PLFA profiles from a microbialite-derived pure culture were analyzed under various growth conditions to assess environmental influences on microbial PLFA composition. Although the majority of the δ¹³C values of Kelly Lake microbialite surface carbonates fell within the range predicted for equilibrium precipitation, samples collected from 26 m were found to have enriched δ¹³C_carb values and are likely a biosignature of autotrophy at this depth. PLFA profiles and δ¹³C_PLFA values also supported the predominance of autotrophy, however, they indicated that heterotrophic organisms were also present. This data suggests that autotrophic metabolisms have influenced the local geochemistry in the past, at least at 26 m, and are likely substantial contributors to microbialite growth. Changes in temperature, pH, NaCl concentrations, and cell densities were found to induce variations in the PLFA profiles of the Exiguobacterium strain RW2. The degree of PLFA unsaturation changed in each of the different culture conditions, and was predominantly adjusted through alterations in the branched monoenoic PLFAs, particularly i-17:1Δ⁵. These results highlight the difficulties associated with applying PLFA profiles as evidence for shifts in a microbial community composition, since altered growth conditions can induce intra-specific PLFA changes.

Master of Science (MSc)

Advisors/Committee Members: Slater, Greg F., Geography and Earth Sciences.

▼ 

The literature on the topic of suburbia is vast. Most studies however, have been written from the point of view of suburban outsiders. Very few scholars have asked suburbanites what they think about the neighbourhoods in which they live. This gap is significant because of our growing awareness of various problems associated with the suburbs, notably those connected to the environment and human health. Focusing on Hamilton, Ontario, this thesis addresses this gap, looking at what suburbanites think about the suburbs in general, as well as their own neighbourhoods. Semi-structured interviews were conducted with 30 residents of single-family, detached dwellings in three neighbourhoods in Hamilton that on most criteria would be considered suburban. Most notably, it was found that suburban residents have difficulty conceptualizing suburbia when asked to define it abstractly, but have less difficulty completing this same task when asked to consider a real-world example instead. As well, it appears that most suburban residents have heard very few positive comments about the suburbs from outside sources. Other findings relate to where suburban residents consider the suburbs to be located in Hamilton, what they think about the negative complaints that have been directed at the suburbs by critics, and what advantages and disadvantages they associate with living in a suburban neighbourhood. These results may have important implications for future research on how suburbanites perceive the suburbs, and for policies aimed at reshaping the suburbs to reduce social, environmental, and economic costs of the suburban lifestyle.

Master of Arts (MA)

Advisors/Committee Members: Harris, Richard, Geography and Earth Sciences.

▼ 

This research demonstrates a method of data collection to analyse and compare flows of bicycle (with historic data) and pedestrian activity using automatic counters and manual counts in Santiago, Chile. An outstanding challenges facing planning for non-motorized transportation (bicycle and pedestrian) is the lack of consistent information on usage and demand of these modes. This is probably the single greatest impediment to being able to understand the behaviour of travelers using these modes. Further, without consistent and accurate information on demand and usage, it is difficult to measure the real benefits of public investments on health, travel time, and other relevant indicators, and to compare these modes to alternatives such as public transit or private automobile. For these reasons, this research aims to measure bicycle and pedestrian activity in specific points of Santiago-Chile. This study is divided into two sections: 1. Measuring bicycle activity in behaviour s of Antonio Varas Ave. and Simon Bolivar Ave. (Case study 1) and Pocuro Ave., Antonio Varas Ave. and Andrés Bello Ave. (Case study 2); and 2. Measuring bicycle and pedestrian activity in the Metropolitan Park of Santiago. This research is designed to (a) evaluate existing bicycle and pedestrian data sources, (b) conduct comprehensive counts of bicyclists and pedestrians using automatic and manual counting methods and (c) analyze the growth rate of bicycle users. This research presents materials developed including a literature review, research objectives, data collection methodology, results from the data collection effort, analysis, conclusions and future recommendations.

Master of Science (MSc)

Advisors/Committee Members: Paez, Antonio, Geography and Earth Sciences.

▼ 

<h1>This study discusses energy and water balance in an 80-year-old deciduous Carolinian forest in the Great Lakes region in southern Ontario, Canada. The eddy covariance technique and associated meteorological and soil variables were used to make a year-round measurements of energy and water vapour fluxes from January-December,2012. This site is part of the Turkey Point Flux Station and global Fluxnet. The linear relationship between daily turbulent (sensible heat (H), latent heat (LE)) and radiative fluxes (net radiation (Rn),soil heat (G) and canopy heat storage ( S)) has a the slope of 0.75 (intercept of -15.8 Wm^-2, and a correlation coefficient, r² of 0.93) indicating a 25% deficiency in energy balance closure. The mean value of canopy albedo was 0.16 during the growing season. Maximum daily evapotranspiration (E) rate was 3.8 mm day^-1 in June, when growing is at its peak in the region. Total annual E was 400 mm, which accounted for 42% of the total annual precipitation of 950 mm. The water storage in upper soil column (1.0 m depth) was approximately 100 mm, indicating that about 450 mm of water was lost from the forest as runoff. Apart from radiation, vapour pressure deficit (D) was the dominant control on E. Maximum value of bulk surface conductance (Gs) was about 18.5 mm s^-1. Gs linearly decreased in response to increase in D. The minimum Gs values were recorded when D was maximum, i.e. 3 to 3.5 kPa. Gs also showed high sensitivity to the volumetric soil water content (ϴ), during dry periods, for example the drought event in 2012. In the growing season, the typical value of Priestley-Taylor α ranged between 0.8 to 1.2 with a maximum of 1.8, indicating a wet deciduous forest. However, the LE/Rn relationship showed a linear increase with increasing D with a low (0.26) slope, indicating a conservative response of forest E to atmospheric demand. This study provides insight into energy partitioning, the water balance and their controls in this Carolinian deciduous forest. A better understanding of evapotranspiration processes and their controls in these forests would help to better quantify water availability at local and regional scales and to evaluate the impacts of future climate change on water resources in the region.</h1>

Master of Science (MSc)

Advisors/Committee Members: Arain, M. Altaf, Geography and Earth Sciences.

▼ 

Investigating the presence of microbial communities in the Earth's deep terrestrial subsurface and the metabolic processes taking place in these environments provides insight into the some of the ultimate limits for life on Earth, as well as the potential for microbial life to exist within the subsurface of other planetary bodies. This Master's thesis project utilized phospholipid fatty acid (PLFA) analysis, in combination with carbon isotope analyses (δ¹³C and Δ¹⁴C), to explore the presence and activity of microbial communities living within deep terrestrial subsurface fracture water systems and low permeability, deep sedimentary rocks. Deep fracture water systems, ranging from 0.9 to 3.2 km below land surface, were sampled for microbial communities via deep mine boreholes in the Witwatersrand Basin of South Africa. PLFA concentrations revealed low biomass microbial communities, ranging from 2x10¹ to 5x10⁴ cells per mL and the PLFA profiles contained indicators for environmental stressors, including high temperatures and nutrient deprivation. δ¹³C and Δ¹⁴C analyses of PLFAs and potential carbon sources (dissolved inorganic carbon (DIC), dissolved organic carbon (DOC) and methane) identified microbial utilization of methane in some systems and utilization of DIC in others. Evidence for microbial oxidation of methane and chemoautotrophy in these systems is consistent with a self-sustaining deep terrestrial subsurface biosphere that is capable of surviving independent of the photosphere. Viable microbial communities were also identified within deep (334 to 694 m depth) sedimentary rock cores sampled from the Michigan Basin, Canada. PLFA analyses revealed microbial cell densities ranging from 1-3 x 10⁵ cells/mL and identified PLFA indicators for environmental stressors. These results demonstrate the ubiquity of microbial life in the deep terrestrial subsurface and provide insight into microbial carbon sources and cycling in deep microbial systems which may persist in isolation over geologic timescales.

Master of Science (MSc)

Advisors/Committee Members: Slater, Greg, Geography and Earth Sciences.

▼  Obesity is a major public health issue across all age groups. The obesity-related health outcomes of children and adolescents are unique and varied, and therefore need to be studied separately. In response, obesogenic environments have been the focus of attention in recent research. Important contributions have been made to focus on social (e.g., economic) and physical (e.g., geographical) environments based on their role in either hindering or facilitating opportunities for healthy eating. However, research on the policy environment is noticeably absent. Schools have been the setting for focused interventions, particularly in the area of obesity and nutrition. However, there is a paucity of research in this area in Ontario, and virtually no Canadian research has examined the secondary school setting. Therefore, this research focuses on local level factors shaping school nutrition policy implementation in Ontario, Canada. The Analysis Grid for Environments Linked to Obesity (ANGELO) Framework was adopted to organize and conceptualize the local level policy environment. In the first phase of the study, a documentary analysis was undertaken to investigate the relationship between regional and upper level policies and technical reports. Results reveal distinct differences across federal, provincial and regional levels, including: 1) the availability of nutritious food in schools and having nutrition education as part of the curriculum were key components of the physical environment across federal and provincial levels; 2) federal and provincial priorities are guided by a health promotion framework, and a partnership approach to policy implementation; and, 3) gaps in regional level policy include incorporating nutrition education in the curriculum, and making the link between nutrition and obesity. The second phase of study includes qualitative key informant interviews with community-and school-level school nutrition policy and program stakeholders (n=22) in nine schools three Ontario school boards, in order to understand local level factors shaping school nutrition policy implementation. The cost of healthy food for sale, revenue loss (economic), proximity of schools to off site food outlets (physical), the restrictive nature of policy, and the role of key stakeholders (political), the role of stigma and school culture (sociocultural), act as local level barriers to policy implementation. Findings suggest the need for consultation and communication between stakeholders, and strategies to reduce stigma and improve the school nutrition culture. In the third and final phase of study three focus group interviews were conducted with secondary students (n=20) in two Ontario school boards in fall 2012. School boards were selected to represent both high-and low-income neighbourhoods. Results reveal high priced policy-compliant food for sale, lower revenue generation capacity, and more students purchasing food off-campus at nearby outlets. Limited designated eating spaces, and time constraints act as… Advisors/Committee Members: Elliott, Susan J., Wilton, Rob, Geography and Earth Sciences.

▼ 

In recent years, paid work has taken on greater meaning for people living with mental illness. Paid work offers the chance to earn a wage, as well as opportunities for improved self- esteem, greater community participation and can reduce the chances of re-hospitalization. Although employment can offer many rewards, access to mainstream employment for people with mental illness remains been difficult as they often face discrimination and a lack of workplace accommodation. One response to these challenges has been the creation of social enterprises as ‘alternative spaces’ of employment for people with mental illness. Social enterprises are organizations with an entrepreneurial orientation whose focus is building social capacity rather than profit maximization. However, relatively little is known about the kinds of organizations that exist for people with mental illness in Ontario. This thesis uses data from key- informant interviews with organizations across Ontario to document the types of social enterprises that exist. The analysis also critically examines the strategies used by organizations to create jobs that are both suitable for people with mental illness, but also conducive to the ongoing success of the social enterprise.

Master of Arts (MA)

Advisors/Committee Members: Wilton, Rob, Geography and Earth Sciences.

▼  Urban expansion and agricultural growth are placing significant stresses on existing groundwater reserves hosted within Quaternary sediments in southern Ontario. Preserving the quality and quantity of groundwater resources requires a detailed knowledge of the three-dimensional distribution of subsurface geologic units. In this study, integrated analysis of surficial sediment exposures, geophysical and remotely-sensed data, and fully-cored boreholes in the Alliston region of southern Ontario has allowed for the identification of landform-sediment associations, or landsystems, which can be used to predict the nature of subsurface sediment types and to assist with the reconstruction of paleoenvironmental change in the region. The landsystems identified in the Alliston region can also be used as a foundation for the development of a stratigraphic framework for hydrogeological investigations. Nine landsystems were identified in the study area and include: i) bedrock escarpment, ii) gravel bench, iii) V-shaped valleys and fills, iv) streamlined uplands, v) low-relief uplands, vi) upland plains and scarps, vii) erosional amphitheatres, viii) hummocky terrain, and ix) lowland plains. These landsystems record the changing distribution of glacial, ice-marginal, glaciofluvial, glaciolacustrine, and post-glacial depositional systems that affected the region during the late Quaternary. The landsystems analysis approach provides a useful framework for discerning the spatiotemporal relationship of a complex suite of depositional systems. Analysis of the distribution and internal composition of landsystems in the study area has allowed the development of a preliminary risk assessment map for aquifer vulnerability in the region. Detailed analysis of 56 outcrop exposures in cutbanks along the Nottawasaga River within the former Lake Algonquin plain has led to the identification of six lithofacies associations (FA 1–6) that present a detailed record of environmental change during the deglacial period. The stratigraphy is floored by the Late Wisconsin Newmarket Till (FA 1) which is locally overlain by ice-proximal debris flows (FA 2). These glacial sediments are overlain by glaciolacustrine silt rhythmites (FA 3) that pass upwards into deltaic sand (FA 4) and channelized fluviodeltaic sand and gravel (FA 5). Lying above the fluvial deposits and capping the succession are widespread sand and silt rhythmites (FA 6), which coarsen up-section. These six facies associations provide a record of changing environmental conditions that existed during deglaciation of the region and give valuable insights into the nature of the evolution of glacial lakes Schomberg, Algonquin, and Nipissing. The deglacial environmental changes described from southern Simcoe County may be valuable analogues for the interpretation of regional-scale events that occurred in extensive lake basins in other formerly glaciated regions. Qualitative observations of groundwater discharge from sediment facies at outcrop faces along the Nottawasaga River… Advisors/Committee Members: Eyles, Carolyn H., Geography and Earth Sciences.

▼  Surface mining of Alberta’s oil sands has led to significant land disturbance, making reclamation and sustainable development of this resource one of the largest challenges facing the industry today. Syncrude Canada Ltd. has developed an innovative technique to reclaim composite tailings (CT) through constructed wetland landscapes and is currently investigating the viability of a pilot-scale freshwater fen built over sandcapped CT. Unpredicted by abiotic geochemical modelling of CT behaviour, a minor episode of hydrogen sulfide (H₂S) gas release was encountered during the initial stages of fen construction indicating microbial activity was likely involved in H₂S generation within CT. This thesis investigates the S geochemistry of CT with depth and employed 454 pyrosequencing and functional enrichments to characterize the associated microbial communities in the first S biogeochemical study of oil sands CT. Porewater H₂S was detected extensively throughout the deposit with background levels ranging from 14 – 23 µM and a maximum of 301.5 µM detected at 22-24 m of depth. Reduced Fe (Fe²⁺) was also detected, but confined within surficial depths sampled, ranging from 1.2 – 38.5 µM. Mass balance calculations identify that the Fe²⁺ generated within the surficial zone of the CT deposit is sufficient to effectively sequester ambient concentrations H₂S generated in this deposit through FeS precipitates. Results identifying (1) distinct zones of porewater Fe²⁺ and H₂S, (2) co-occurrence of the highest [H₂S] and lowest dissolved organic C (DOC) at 22-24 m consistent with heterotrophic sulfate reducing bacteria (SRB) activity, and (3) the presence of mixed valence Fe biomineral, magnetite, throughout the deposit, are all consistent with microbially-mediated Fe and S cycling occurring within this CT deposit. The cultivation independent identification of several known iron reducing bacteria (IRB) and SRB within CT microbial communities, in conjunction with observed positive growth of IRB and SRB functional metabolic enrichments, demonstrates widespread capacity for microbial Fe and S activity throughout the CT deposit. Metagenomic characterization of CT microbial communities revealed high diversity (over 20 phyla) over the 5 depths examined. Multivariate statistical analyses (Unifrac) revealed that bacterial community composition and structure was driven by changed in DOC, ORP and salinity and that structuring corresponded with a surficial zone of Fe³⁺ reduction and an underlying zone of SO₄^2- reduction. Despite the high organic carbon (OC) content of oil sands tailings, much of that C is not considered to be labile and accessible to microbes. Based on the results of this thesis, CT SRB appear to have a greater ability than IRB to utilize recalcitrant OC (e.g. bitumen, naphthenic acids) given the widespread occurrence of porewater [H₂S] and surficially restricted [Fe²⁺] despite… Advisors/Committee Members: Warren, Lesley, Geography and Earth Sciences.

▼ 

Magnetic surveys are one of the principal geophysical methods employed to map the structure of basement rocks deeply buried below cover strata. In resource studies, aeromagnetic surveys are commonly acquired at regional scales (100-1000’s km2) while very few studies have attempted to resolve basement structures at site-scale (<10 >km2). In this study, high-resolution lake-based magnetic survey methods were evaluated for mapping of deeply-buried basement faults (Küçükçekmece Lagoon, Turkey; 6 km2) and a suspected meteorite impact crater (Charity Shoal, Lake Ontario; 9 km2). Total magnetic intensity (TMI) surveys were acquired using a single Overhauser magnetometer with 50-150 m line spacing. Interpretation of the magnetic data was aided by forward modelling of TMI data and depth to basement estimates using Euler and analytic signal methods. Total magnetic intensity (TMI) maps of Küçükçekmece Lagoon identify several north-northwest trending (340-350°) magnetic lineaments that are aligned with strike-slip faults mapped from offshore seismic data. The pattern of magnetic anomalies in the lagoon is consistent with extensional normal faulting of bedrock and lake sediments. Magnetic results from Charity Shoal reveal a large (>1400 nT) parabolic-shaped magnetic anomaly centered over the crater basin and an annular magnetic high (40-50 nT) corresponding with the basin rim. Modelling results exclude the origin of the CSS as a shallow glacial erosional or karst sinkhole feature and are most consistent with a pre-Paleozoic meteorite impact in the Precambrian basement.

Master of Science (MSc)

Advisors/Committee Members: Boyce, Joe, Geography and Earth Sciences.

▼ 

Modern advances in biometeorological monitoring technology have improved the capacity for measuring ecosystem exchanges of mass, energy and scalars (such as CO₂). Translating these measurements into robust and accurate scientific information (and ultimately, understanding) requires careful assessment of operations throughout the biometeorological data life cycle. In response, this research analyzed and optimized aspects of data collection, management and filtering for an ecosystem exchange measurement program over an age-sequence of temperate white pine forests. A comprehensive data workflow and management system (DWMS) was developed and implemented to support the entire data life cycle for all past, present and future measurement operations in our research group, and meet the needs of a collaborative, student-led data management environment. Best practices for biometeorological data management were introduced and used as standards to assess system performance. Roving eddy covariance (rEC) systems were examined as a means of producing reliable time-integrated carbon exchange estimates at multiple sites, by rotating an EC system in a resource-mindful approach. When used with an optimal gap-filling model and rEC rotation schedule (2 sites with 15-day rotations), the results suggested its viability, as annual NEE estimate uncertainties ranged between 35 and 63% of the annual NEE flux magnitude at our study sites – even though approximately 70% of half-hours were filled. Lastly, a data-driven approach was used to investigate the effects of different friction velocity and footprint filtering methods on time-integrated carbon exchange estimates at our fetch-limited forests. Though predicted flux source areas varied considerably between footprint models, our objective analyses identified the model (Kljun et al., 2004) and within-fetch requirement (80%) that optimized reliability and representativeness of carbon exchange estimates. Applying this footprint model decreased annual NEE by 31 to 129% (59 to 207 g C m^-2 y^-1) relative to no footprint application, and highlighted the importance of objective analyses of EC flux filtering methods.

Doctor of Philosophy (PhD)

Advisors/Committee Members: Arain, M. Altaf, Geography and Earth Sciences.

▼ 

In the first paper, sense of place (SoP) is used to evaluate immigrant experiences in three small to medium-sized Canadian cites: Hamilton, ON; Saskatoon, SK; and, Charlottetown, PEI. First, quantitative analysis is used to compare SoP amongst immigrant and Canadian-born respondents in the three cities. Ordered logistic regression determined four significant predictors of SoP: income; age; neighbourhood length of residence and, city of residence. Despite an observed difference in evaluations of SoP between immigrants and Canadian-born individuals, regression analysis did not identify immigrant status as a significant predictor of SoP. The second paper employs a mixed-methods strategy to examine individual perceptions of air quality and sense of place amongst Canadian-born and immigrant women in Northeast Hamilton. Furthermore, the study aims to determine the influence of sense of place on local environmental perceptions. Qualitative focus group discussions suggest that Canadian-born women may be more aware, knowledgeable and concerned about large-scale air quality issues; however, the tension between economic and environmental needs hinders their sense of control. Quantitative survey results suggest that Canadian-born residents have a higher absolute value of sense of place than immigrants. Bringing together the qualitative and quantitative data suggests that sense of place may inform environmental perceptions.

Master of Arts (MA)

Advisors/Committee Members: Williams, Allison, Geography and Earth Sciences.

▼ 

Surface mining is a common method of accessing coal. In high-elevation environments, vegetation and soils are typically removed prior to the blasting of overburden rock thereby allowing access to mineable ore. The removed waste rock is deposited in adjacent valleys where it may bury existing streams. Previous research, predominantly in Appalachia, has focused on downstream water quality impacts with less focus on how streamflow response and flow pathways are affected by surface mining. This study reports on how surface mining affects streamflow hydrological and chemical responses at the headwater catchment scale in the Elk Valley, British Columbia. A paired catchment approach was utilized between May and October 2012, where a reference catch- ment (Dry Creek - DC) was compared to an impacted catchment (West Line Creek - WLC), whose area is 30% covered by deposited waste rock. Hydrometrically, WLC had considerably lower flows and exhibited a damped, slower response to precipitation events than DC. Dissolved ions were an order of magnitude greater in WLC, with conductivity (SpC) ranging between 400 μS/cm at high flow to 1300 μS/cm at low flow. A strong hysteretic pattern was observed between SpC and flow and with specific ions at WLC, suggesting dilution or changing flowpaths as the season progressed. In contrast, patterns of SpC and flow at DC did not exhibit hysteresis. Major ion hydrochemistry at WLC shows dilution affecting ion concentrations whereas results at DC are consistent with chemostatic behavior. Stable isotopes were more depleted at DC compared with WLC, suggesting different sources and timing of water contributing to streamflow. Future research will work towards a conceptual model of surface mining impacts on catchment scale processes in montane environments through increased understanding of residence time and flowpath distributions at a number of impacted and reference catchments.

Master of Science (MSc)

Advisors/Committee Members: Carey, Sean, Geography and Earth Sciences.

▼ The carbon and nitrogen coupled dynamic vegetation model, CLASS-CTEMN+ combines process-based, large-scale representations of terrestrial vegetation dynamics and land-atmosphere carbon and water exchanges in a modular framework. It prognostically simulates the principal processes of the terrestrial biosphere carbon and kinetic energy exchanges at the soil surface and plants, as well as the dynamic soil-plant nitrogen cycles. In this study, improvements made in parameterization of different plant functional types (PFTs) were evaluated, and then, model was used to assess the effects of nitrogen controls on simulated terrestrial carbon, water and energy exchanges and carbon pools from the site-level to regional and global scales. Prior to global simulations, standardized hourly meteorological forcing data, eddy covariance (EC) fluxes, and other site-specific observations from 39 FLUXNET sites from the North American Carbon Program (NACP) and the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) projects, spanning 194 site-years and covering 8 major PFTs across the North America and the Amazonian basin, were used to evaluate model performance. Two versions of the model, carbon and nitrogen coupled (C-N) version and carbon-only (C) version were used to simulate diurnal, daily, seasonal and annual values of carbon, water and energy fluxes at each site. Carbon pools and key nitrogen cycling variables were compared to investigate nitrogen controls on carbon, water and energy exchanges at each site. On the global scale, gridded forcing and initializing data sets developed by the North American Carbon Program (NACP)-Multi-Scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) were used in CLASS-CTEMN+ simulations at 0.5 × 0.5 degree spatial resolution from 1901 to 2010. Exploratory and diagnostic assessment of the model was conducted at the global multi-decade scale, by comparing results from both versions of the model with observational and modeled estimates from literature to determine the impact of nitrogen availability on spatiotemporal dynamics and distributions of terrestrial carbon, water and energy fluxes and C pools. Model results revealed satisfactory performance of the model in simulating carbon, water and energy fluxes and carbon stocks, when compared to observations, especially in summer, and at evergreen needleleaf forest ecosystems. In contrast, simulation-observations agreement declined in winter and early spring, and at non-forested sites (crops and grassland), especially in dry periods during the growing season. The C-N coupled model simulated global total mean annual estimates from 1980-2010 for Gross Ecosystem Productivity (GEP, 122.7 Pg C yr−1), Ecosystem Respiration (Re, 119.1 Pg C yr−1), Net Ecosystem Productivity (NPE, 3.46 Pg C yr−1), Net Primary Productivity (NPP, 57.1 Pg C yr−1), Latent Heat (LE, 146.2 ZJ yr-1), Sensible Heat Flux (H, 194.0 ZJ yr-1), Soil Organic Carbon (SOC, 1230.0 Pg C) and Total Vegetation Biomass (Tvg, 608.0 Pg C) were similar to reported values… Advisors/Committee Members: Arain, M. Altaf, Geography and Earth Sciences.

▼ 

Immigrants are an important part of Canada and Canadian culture. Despite a large number of immigrants in Canada relatively few studies have focused on disability and immigrants. Even less research has been conducted on immigrants with visual impairments. The first paper uses the Participation Activity Limitation Survey (PALS) from 2006 to examine the prevalence of vision impairment in immigrants compared to non-immigrants, 50 years of age and over. First, descriptive statistics were used to determine the prevalence rate of vision impairment. Then, multivariate logistic regression was utilized to examine differences in providers of support and characteristics of individuals who receive support. Results disclosed that there was no difference in the prevalence rates of adult immigrants and non-immigrants over 50 years of age when controlling for age and gender. Results confirmed that there is a relationship between having a vision impairment and living in a low income household. Results also showed that receiving support is linked to severity of impairment. The second paper used qualitative analysis to examine visually impaired immigrants’ perception of vision impairment and disability and if perception influenced utilization of care. Qualitative semi-structured interviews were conducted with 8 clients of the Canadian National Institute for the Blind (CNIB). Results showed that immigrants’ employ three different views when explaining their impairment, these were; the medical view, social view and theological/ traditional view. All participants used two or more views interchangeably demonstrating that all views are important in understanding how immigrants perceive and navigate their impairment on an everyday basis. Results also suggested that negative perceptions did not keep most immigrants from accessing services; however, traditional barriers such as not being eligible to receive services and transportation were main barriers.

Thesis

Master of Arts (MA)

Advisors/Committee Members: Newbold, Bruce K., Geography and Earth Sciences.

▼ 

Water-associated diseases are a significant cause of morbidity and mortality worldwide and are a barrier to sustainable development in many regions. Human pressures on the environment resulting in large-scale changes to land and water resources have been implicated in these health challenges. In this context, developing sustainable interventions requires a more integrative understanding of the complexity and relationships between these processes, as well as policy-relevant research that supports decision-makers. By applying a vulnerability framework to water-associated disease, this dissertation explored social and ecological determinants that mediate transmission at different scales. Vulnerability was conceptualized as the propensity of a system to be adversely impacted by a water-associated disease, described by dimensions of exposure, susceptibility and resilience. Based on this framework, a water-associated disease index (WADI) and mapping approach was developed, and applied to the case of dengue at a national level in Malaysia. The findings identified heterogeneous patterns of vulnerability, including regions experiencing consistently low and high vulnerability, as well as areas with changing conditions due to strong seasonal exposure. The WADI was further applied to assess the dynamic nature of vulnerability to water-associated disease in northeastern Brazil. Changes across the region due to short-term seasonal trends as well as long-term trends between time periods 2000 and 2010 were identified. These findings illustrated the importance of long-term global environmental changes such as land use intensification and growing urban population density, as well as short-term seasonal changes. In addition to the WADI analysis, qualitative research at a local level was conducted to investigate spatial perceptions of vulnerable places within a community. Findings illustrated different understanding of mosquito breeding sites among residents in the study areas, suggesting potential differences in susceptibility to dengue despite similar levels of exposure on a large scale. Overall, this dissertation highlights the need for a comprehensive understanding of vulnerability to water-associated disease, achieved by considering complex spatiotemporal relationships as well as local perspectives.

Thesis

Doctor of Philosophy (PhD)

Advisors/Committee Members: Schuster-Wallace, Corinne, Geography and Earth Sciences.

▼ 

Violent crime which is referred to as crime against persons has been recognized as the most serious species of crime. Violent crime imposes monetary costs, psychological costs, and social stability disruption. Incarceration strategies used in several societies have been inefficient in deterring, incapacitating, and rehabilitating offenders of violent crime. Additional approaches to preventing and reducing violent crime are needed. This dissertation aims to address three objectives. First, empirically investigate the temporal stability of socio-economic covariates of violent crime. Second, investigate the persistence of violent crime hot spots over time, and the socio-economic factors that correlate with said persistence. Third, develop a Google Street View-based environmental audit approach to quickly and systematically collect environmental data, and explore the role of physical features of built environment in inducing and deterring violent crime. The results of model parameter analysis indicate that it is unnecessary to average crime over multiple years if model parameters are stable across years. The results of hot spots persistence analysis suggest that a combination of social disorganization theory and routine activity theory provides an applicable framework for understanding the temporal dimension of violent crime hot spots. By identifying the factors that contribute to the persistence of hot spots of crime, insights gained from the results can help to inform focused crime prevention practices. The results obtained from Poisson regression with spatial filtering and Google Street View-based environmental audit provide a series of environmental correlates of violent crime, and provide both theoretical and practical implications for several theories of crime and crime prevention efforts.

Dissertation

Doctor of Philosophy (PhD)

Advisors/Committee Members: Páez, Antonio, Geography and Earth Sciences.

▼ The generation of acid and H2S associated with microbial cycling of intermediate sulfur species, (sulfur oxidation intermediates; SOIs), is a global mining industry management issue. Both the role of bacteria in SOI transformations as well as comprehensive understanding of the SOIs that can occur within mining wastewaters, are poorly constrained. Key impediments to the industry’s ability to improve wastewater sulfur management have been securing a better understanding of the specific sulfur oxidation intermediate (SOI) species that occur in wastewaters, as well as microbial transformations of these sulfur species. One of the significant prohibitions on the advancement of knowledge in the area of SOI transformations in mine waste waters has been the lack of analytical methods for these species as well as lack of understanding of the controls on these transformations. A significant step forward was established through the development of robust analytical methods using derivatization and HPLC analysis to characterize sulfite (SO32-), thiosulfate (S2O32-), sulfide (H2S) as well as elemental sulfur (S0). These methods enabled assessment of these sulfur compounds in >60 seasonally and spatially varying wastewater samples collected from Sept 2014 to May 2016. Results identified SOIs were present in all wastewater samples and there were seasonal variations in both concentrations and occurrence of specific SOIs. The mass balance analysis of bulk water samples show that the total sulfur concentration varies seasonally in the system. Higher total sulfur occurred during spring and summer (8.4-13.1 mM) with lower (5.3-10.8 mM) total sulfur observed during the fall and winter sampling campaigns. Further, the proportion of the total sulfur pool associated with sulfate, indicative of complete oxidation of sulfur, were highest during spring and summer (75-100%) with a decreasing trend through fall (60-75%) and lowest in the winter under ice (10-20%); suggesting temperature may be an important ecological control on sulfur redox biogeochemistry. Corresponding to the observed decreasing seasonal sulfate trend, an increasing trend in the proportion of unanalyzed sulfur species (e.g. S4O62-, S2−n+1, SnO62-) was also observed, increasing from 0-25% (spring, summer) to 80-90% under ice. Further, elemental sulfur (S0), which emerged as an important part of the sulfur cycle in these waters, ranged in proportional abundance from 25-99% of the analyzed sulfur species. Elemental sulfur increased during the fall and winter (75-99%), compared to 25-65% during the spring and summer. Enrichment of sulfur oxidizing microbes (SOM) was conducted to determine whether SOM’s were present in endemic waters, and if so, what were the controls on these microbes in terms of cycling SOI’s and producing protons. Enrichment experiments were successful from all >60 water samples collected indicating the presence of these bacteria throughout the system over seasonal scales. These SOM catalyzed sulfur transformations consistent with the seasonal SOI… Advisors/Committee Members: Warren, Lesley, Geography and Earth Sciences.

▼ Speleothems (cave carbonate deposits) have been recognized as a multi-proxy paleoclimate archive. Variations in carbon and oxygen isotopes in speleothems can record past climate changes (e.g., temperature, rainfall and vegetation) under isotopic equilibrium conditions. However, non-climatic noises caused by in-cave processes may affect these stable isotope records under non-equilibrium isotopic conditions. The identification of equilibrium and non-equilibrium isotopic conditions in speleothems is still disputed in the speleothem research community; however, this is a prerequisite for the interpretation of carbon and oxygen isotope records in speleothems as paleoclimate proxies. In this Ph.D. thesis, a series of laboratory experiments under cave-analogue conditions were performed to simulate the formation of speleothems in natural caves. The results of these experiments demonstrate that stable isotope equilibrium in speleothems is achieved under slow carbonate precipitation in pool-like settings (pool carbonates). On the basis of these pool carbonates, equilibrium carbon and oxygen isotope fractionation factors between calcite and water (or DIC for carbon) were determined. Our experiments show larger carbon and oxygen isotope non-equilibrium fractionations between calcite and water (or DIC for carbon) in stalagmite-like settings (fast carbonate precipitate) than those determined in pool-like settings. The flow rate of drip water above the surface of stalagmite appears to control the magnitude of these non-equilibrium isotope effects which increase with decreasing the flow rate. Furthermore, a natural speleothem sample was examined as a paleoclimate archive in this thesis. The growth of a double stalagmite (WS-5d) in Wadi Sannur Cave from the Northeastern Sahara was used to infer the greening of the Sahara (intensive rainfall and vegetation). The U/Th dating in the WS-5d stalagmite suggests that greening conditions extended widely in the Sahara during the interglacial Marine Isotope Stages MIS 5.5, MIS 7.3, and the early MIS 9. Based upon oxygen isotope compositions from the WS-5d, we attributed the source of these greening periods to long-traveling rains from the Atlantic Ocean that were delivered via the West African monsoon system. Our study suggests that the two youngest greening periods were concurrent with the arrival of Homo sapiens in the Levant and an earlier possible change in human population at 244 ka, indicating a key role of the Sahara route in early human dispersal out of Africa. Finally, clumped isotope measurements (Δ47) on carbonate-derived CO2 have been shown to reflect the formation temperature of the carbonate minerals. The absolute Δ47 values of these isotopic measurements seem to be sensitive to the standardization methods (heated CO2 gases and water-equilibrated CO2 gases) that are used to normalize the raw Δ47 measurements. Neither the hypothetical base for the heated CO2 gas standardization method nor the theoretical base for the water-equilibrated CO2 gas standardization method has been… Advisors/Committee Members: Kim, Sang-Tae, Geography and Earth Sciences.

▼ 

PhD Thesis

On congested North American urban road networks, driver concerns over increased travel time play a major role in whether or not cycling infrastructure is built. This fact is recognized by transportation planning agencies in Canada and the United States, including the Ministry of Transportation Ontario and the Federal Highway Administration. However, specific frameworks to address such driver concerns do not exist within the practice of urban planning nor the academic literature. One potentially fruitful avenue is to explore the methods and tools of critical link analysis. One such avenue is provided by the Network Robustness Index (NRI) and the Network Robustness Index Calculator, as this method and tool indexes critical links through traffic simulation from least to most critical. The specific information that can be used to address driver concerns is found in the least critical links as these roadways have additional capacity, and therefore may be considered underutilized. This thesis explores the use of the NRI as a framework for urban cycling infrastructure planning. Experiments on the utility of the NRI against common traffic and cycling planning tools are explored. The NRI Calculator’s ability to perform full network scans for potential bike lane locations, least cost corridors, and full cycling networks consisting of different designs is tested throughout the chapters of this manuscript.

Thesis

Doctor of Philosophy (PhD)

This thesis aids in the planning of urban bike lanes by addressing driver concerns through traffic simulation.

Advisors/Committee Members: Scott, Darren, Geography and Earth Sciences.

▼ 

Understanding how organic matter is microbially cycled through Bangladesh aquifers is a key component in understanding the spatial and temporal patterns of arsenic release into groundwater occurring on wide regional scales. There is a current gap in the literature for how overall microbial carbon cycles are functioning in Bangladesh aquifers, how these microbial metabolisms factor into arsenic release, including methodology as to approach these questions in situ. This research aimed to provide insight into carbon sources and cycling of the microbial communities in Bangladesh aquifers through a complimentary applied suite of lipidomic, isotopic and inorganic analytical approaches on in situ sediments and groundwater from Bangladesh aquifers. Through radiocarbon analyses of phospholipid fatty acids (PLFA's), bacterial populations in a shallow Holocene-aged and high arsenic aquifer were found to be predominantly utilizing younger organic matter as their carbon source rather than older sedimentary carbon. At the sites studied, the sources of younger organic matter that coincide with zones where increased reductive dissolution of iron and arsenic release is occurring were consistent with human and livestock waste identified through sedimentary sterol distributions (phytosterols and coprstonaol) and Cl/Br mass ratios in groundwater. Since poor sanitation is widespread across Bangladesh, sewage-derived waste should be considered a prevalent potential microbial carbon source is these systems. An examination of sediment- versus groundwater-associated microbial communities in Bangladesh aquifers (through PLFA analysis) suggested that the former is 5-6 orders of magnitude more abundant than the latter. Archaeal communities, examined through both groundwater methane and sedimentary archaeal lipid (archaeol and glycerol dialkyl glycerol tetraether (GDGT)) analysis, are suggested to be highly active (depths 5-240 m) but to varying degrees in Bangladesh aquifers. Methanogenesis, dominantly being carried out through CO2 reduction, appears to be spatially associated at some sites with zones of iron/arsenic reductive dissolution in the Bangladesh aquifers. The analytical approaches and conceptual frameworks applied throughout this dissertation have been demonstrated to be effective strategies to understand how microbial carbon cycling is occurring at a community level and intimately involved in arsenic release.

Thesis

Doctor of Philosophy (PhD)

Advisors/Committee Members: Slater, Greg, Geography and Earth Sciences.

▼ Coastal karst aquifers are important water resources, often providing the only source of freshwater to coastal communities for agriculture, industrial usage and human consumption. In order to implement management strategies and preventative measures for future perseveration of this resource, it is imperative to understand how coastal groundwater conditions are controlled by the interaction of freshwater/seawater on local and regional scales, but also over recent and past time periods. However, there is a limited resource of published hydrological data on recent aquifer conditions. In the Yucatán Peninsula and other anchialine environments, this lack of information inhibits the understanding of the spatial and temporal interaction of the meteoric and marine water masses. Documenting how the aquifer is responding to forcing mechanisms such as large precipitation events, seasonal cycles and short-term sea level rise (e.g. storm surge) will assist in understanding modern aquifer condition but also the interpretation of paleo-records. Utilization of water level and salinity sensors in strategic positions in the aquifer demonstrate that meteoric water mass salinity varies over wet and dry seasons with the movement of the halocline, but also on a short-term basis though large rainfall events. Salinity in the meteoric water mass is influenced by mixing with the marine water mass during intense precipitation events associated with Hurricane Ingrid (2013), Tropical Storm Hanna (2014) and a series of unnamed events in 2015. During wet periods, induced flow from increase precipitation causes turbulent mixing with the marine water mass, increasing salinity in the upper meteoric lens. On the contrary, during dry periods, mixing is reduced, therefore making the meteoric lens less saline. This contemporary understanding of meteoric/marine water mass dynamics can be applied to developing and calibrating the geochemical record of calcite rafts, calcite precipitation at the air-water interface of cave pools, as a hydrological proxy for aquifer conditions. Our monitoring of calcite raft formation, deposition and geochemistry shows that raft accumulations (e.g., raft piles/cones) can offer a good paleoenvironmental archive of changing hydrological conditions. Based on a 2-year observational record, results indicate that calcite raft precipitation/formation occurs continuously but with only minor biases with intense rainfall events altering supersaturation conditions in the surface waters. Testing the use of calcite rafts in sediment cores from Hoyo Negro show that geochemical analyses (87Sr/86Sr, δ18O, δ13C, Sr/Ca and Cl/Ca) show that meteoric water mass salinity varied during the Holocene (~ 8.5 Ka – present) likely due to changing rainfall and or cave passage geomorphology, which is coherent with other independent climate records. Prior to this study, calcite rafts have never been considered a paleo-hydrological archive for aquifer conditions, however, the consistency and cross-validation with independent records… Advisors/Committee Members: Reinhardt, Eduard G., Geography and Earth Sciences.