Physical Sciences and Mathematics Commons^™

Channel Form And Processes In A Formerly Glaciated Terrain, Nathaniel Bergman

Electronic Thesis and Dissertation Repository

Despite that many places around the world in general, and North America in particular, were glaciated during the last ice age, relatively little is known about rivers that evolved over these landscapes once they deglaciated. These rivers are commonly categorized as alluvial with a glacial legacy, and often described as plain gravel-bed or sand-bed rivers. Alternatively, they are considered to be bedrock rivers when the glacial deposits were eroded and underlying rock was exposed. However, ignoring the glacial history of these rivers is scientifically wrong and they should be termed "semi-alluvial". This work shows that classification is important, not only …

Multiscale Wind Modelling For Sustainability And Resilience, Djordje Romanic

Electronic Thesis and Dissertation Repository

The research presented herein is a mix of meteorological and wind engineering disciplines. In many cases, there is a gap between these two fields and this thesis is an attempt to bridge that gap through multiscale wind modelling approaches. Data and methods used in this study cover a multitude of spatial and temporal scales. Applications are in the fields of sustainability and resilience. This relationship between multiscale wind modelling and sustainability and resilience is investigated examining several case studies of three different developments: urban, rural and coastal.

An urban wind modelling methodology is proposed and applied for a specific development …

Uncertainty Analysis Of The Performance Of A System Of Best Management Practices For Achieving Phosphorus Load Reduction To Surface Waters, Jason D.M. Igras

Electronic Thesis and Dissertation Repository

The repeated occurrence of Lake Erie’s harmful algal blooms suggests an inadequate phosphorus management system that results in excessive loads to the lake. In response, Canadian and United States’ governments have issued a new management objective, a 40% reduction in total and dissolved reactive phosphorus loads relative to 2008. To provide scientific evidence to guide managers toward achieving their management objective, we used the International Organization of Standardization (ISO) 31010 Bowtie Risk Analysis Tool to analyze the performance of the phosphorus management system. The effectiveness of agricultural best management practices (BMPs) and their adoption were combined into a Bayesian belief …

Using Physical And Social Sensors In Real-Time Data Streaming For Natural Hazard Monitoring And Response, Yelena Kropivnitskaya

Electronic Thesis and Dissertation Repository

Technological breakthroughs in computing over the last few decades have resulted in important advances in natural hazards analysis. In particular, integration of a wide variety of information sources, including observations from spatially-referenced physical sensors and new social media sources, enables better estimates of real-time hazard. The main goal of this work is to utilize innovative streaming algorithms for improved real-time seismic hazard analysis by integrating different data sources and processing tools into cloud applications. In streaming algorithms, a sequence of items from physical and social sensors can be processed in as little as one pass with no need to store …

Anthropogenic Particles In Natural Sediment Sinks: Microplastics Accumulation In Tributary, Beach And Lake Bottom Sediments Of Lake Ontario, North America, Anika M. Ballent

Electronic Thesis and Dissertation Repository

Surface waters of the Great Lakes are known to be contaminated with microplastics, however, microplastics in the sediments of the region are poorly documented. This study provides a baseline of micro- and macro-plastics contamination in nearshore, tributary and beach sediments of Lake Ontario and the upper St. Lawrence River. Microplastics were quantified and characterized by morphology and composition using visual identification and Raman spectroscopy. Microplastics are most concentrated in nearshore sediments in the vicinity of urban and industrial regions. Concentrations in Humber Bay and Toronto Harbour consistently measured > 500 particles per kg dry sediment, and maximum concentrations of ~28,000 particles …

Doped Tio2 Nanowires For Applications In Dye Sensitized Solar Cells And Sacrifical Hydrogen Production, Qasem Alsharari

Electronic Thesis and Dissertation Repository

This thesis explores the synthesis of metal oxide 1-D nanowires using a sol-gel method in supercritical carbon dioxide (sc-CO₂), as an environmental friendly enabling solvent. Porous nanowires were synthesized and their performance was tested in dye sensitized solar cell and sacrifical hydrogen production. Titanium isopropoxide (TIP) was used as a precursor for titania synthesis while copper, bismuth and indium were examined as dopants, respectively. The sol-gel reactions were catalyzed by acetic acid in CO₂ at a temperature of 60 °C and pressure of 5000 psi. It was observed that acetic acid/monomer ratio > 4 produced nanowires while a …

The Influence Of Capacity And Attitudes In The Use Of Water Quality Citizen Science And Volunteer Benthic Monitoring In The Freshwater Management Activities Of Ontario’S Conservation Authorities, Sonja Teichert

Electronic Thesis and Dissertation Repository

The contribution of non-experts to environmental management has been significant and continues to flourish through their participation in citizen science. Despite its growth as an interdisciplinary field of enquiry, there are many gaps in our understanding of the role that citizen science may play in the future of environmental management. In Ontario, Canada, due to funding cuts and infrastructural changes over the past two decades, the provincial government’s ability to monitor changes in freshwater resources had been severely limited. This has resulted in downloading water monitoring to municipalities through their conservation authorities (CAs) which are watershed-based, quasi-governmental water management agencies. …

Lagoon Wastewater Effluent Impacts Stream Metabolism In Red River Tributaries, Chris T. Chesworth

Electronic Thesis and Dissertation Repository

Lagoons are the most common form of sewage treatment for rural Canadian communities and may therefore be a major source of pollution to local waterways. However, the environmental effects of pulse releases of lagoon effluent are largely unknown. This study reports on changes in physicochemical conditions and stream metabolism occurring as result of summer lagoon effluent releases into Red River tributaries, Manitoba, Canada. We calculated metrics of stream metabolism using the single-station, open water method. We found that an effluent release results in a significant short-term increase in physicochemical (i.e., water nutrients, stream discharge) conditions which had a subsidy effect …