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Coastal cities are grappling with how to shift their approach in designing the built environment to respond to global warming and sea level rise. With the potential increase of sea level rise by 1 metre by the year 2100, and climate change projecting more intense and frequent storms to British Columbia’s coasts, Vancouver will need to consider more resilient approaches to address flood risk along its shores. One area that will be exposed to flood risks includes the False Creek Flats, a historic tidal flat converted to rail and industrial hub in the core of the city, and on the cusp of transforming into the city’s next employment hub. At present, it is indiscernible that the False Creek Flats at one time was a historic tidal flat with a rich ecology supporting a variety of plants and wildlife, providing food and sustenance to the Indigenous people whose traditional territory included this land. The emergence of the rail and industry erased this history, the connection to the water, and the dynamic coastal processes that shaped the landscape. With the False Creek Flats undergoing a significant transformation over the next number of years, there is a window of opportunity to reconnect False Creek Flats to the coastal landscape, while also making room for flood waters and shifting perspectives on how we live with and build with water. This practicum seeks to develop a resilient design approach for False Creek Flats through three lenses: robustness, ensuring people are safe; adaptive, making room for the water; and transformative, shifting perspectives through design interventions. Leveraging the opportunity to make False Creek Flats resilient to climate change and flooding will benefit Vancouver by creating opportunities to shift public perspectives on how the city should adapt to sea level rise and climate change, while also bolstering public policy that will make the city and its residents more adaptive and resilient to change.

The spring bloom of microalgae within the bottom of sea ice provides a significant contribution to primary production in the Arctic Ocean. The aim of this research was to improve observations of the ice algae bloom using a transmitted irradiance technique to remotely estimate biomass, and to examine the influence of physical processes on biomass throughout the sea ice melt season. Results indicate that bottom ice temperature is highly influential in controlling biomass variability and bloom termination. Snow depth is also significant as it buffers ice temperature from the atmosphere and largely controls transmission of photosynthetically active radiation (PAR). The relationship between snow depth and biomass can change over the spring however, limiting biomass accumulation early on while promoting it later. Brine drainage, under-ice current velocity, and surface PAR in the absence of snow cover are also important factors. Overall this research helps to characterize the spring ice algae bloom in the Arctic by improving in situ biomass estimates and identifying primary factors controlling it.

A CO2 emission analysis and system investigation of a direct fuel cell waste energy recovery and power generation system (DFC-ERG) for pressure letdown stations was undertaken. The hybrid system developed by FuelCell Energy Inc. is an integrated turboexpander and a direct internal reforming molten carbonate fuel cell system in a combined circle. At pressure letdown stations, popularly called city gates, the pressure of natural gas transported on long pipelines is reduced by traditional pressure regulating systems. Energy is lost as a result of pressure reduction. Pressure reduction also results in severe cooling of the gas due to the Joule Thompson effect, thus, requiring preheating of the natural gas using traditional gas fired-burners. The thermal energy generated results in the emission of green house gases. The DFC-ERG system is a novel waste energy recovery and green house gas mitigation system that can replace traditional pressure regulating systems on city gates. A DFC-ERG system has been simulated using UniSim Design process simulation software. A case study using data from Utilities Kingston’s city gate at Glenburnie was analysed. The waste energy recovery system was modelled using the design specifications of the FuelCell Energy Inc’s DFC 300 system and turboexpander design characteristics of Cryostar TG120. The Fuel Cell system sizing was based on the required thermal output, electrical power output, available configuration and cost. The predicted performance of the fuel cell system was simulated at a current density of 140mA/cm2, steam to carbon ratio of 3, fuel utilization of 75% and oxygen utilization of 30%. The power output of the turboexpander was found to strongly depend on the high pressure natural gas flowrate, temperature and pressure. The simulated DFC-ERG system was found to reduce CO2 emissions when the electrical power generated by the DFC-ERG system replaced electrical power generated by a coal fired plant.

Rapidly changing environments impact avian populations greatly. Indeed, variable weather affects the timing of crucial resource availability and behaviours of breeding birds. Migratory birds are particularly threatened by advancing springs and must adjust their migration timing to remain synchronized with spring phenology. Environmental factors such as weather variability are known to influence bird timing both during breeding and migratory periods but have rarely been investigated for their impact across migration routes. Once birds are at their breeding locations, how environmental factors influence local timing and movements has also been little examined. In this study, in a declining long-distance migrant, the purple martin (Progne subis), I first investigate how extrinsic (environmental), and intrinsic (morphological, migration destination) factors impact migration timing and rate. Second, I investigate the timing of parental roosting during active parental care, and how environmental and nest conditions influence this behaviour. I found that variation in destination and timing are the main influence on spring arrival date and migration rate, while to a lesser extent favourable weather promotes faster migration. The great influence of spring departure on migration rate and arrival suggests selective pressure on migration timing across routes to match with conditions at the breeding grounds. I also found that summer roosting is prominent in purple martins with colder evenings and increased parental investment increasing the odds of parents remaining at their colony at night. Overall, my findings indicate that the influence of environmental factors on movement behaviour may vary by season, with spring migration being mostly driven by intrinsic factors, while summer roosting may be most influenced by local temperature. Future research on the effects of environmental factors on migratory stopover duration and the seasonality of roosting would further our understanding of these timing behaviours and how they may interact with advancing climate change.

Ice is a prominent characteristic of water bodies in cold regions. For rivers regulated for hydropower operations, the production of ice particles can result in obstructions and subsequent performance issues during energy production. Rough and thickened ice covers resulting from high flow conditions can also lead to substantial hydraulic losses. While ice formations impact hydropower operations, a river’s flow hydrograph also influences ice processes from freeze-up through break-up. Research investigations into the influence of regulation on ice processes benefits not only hydropower practioners, but also those who are impacted by hydropower operations. Further, understanding these cause-and-affect relationships supports design of innovative tools to quantify the impact of ice on river hydraulics. In this study, a detailed characterization of ice processes is presented for the regulated Upper Nelson River region located at the outlet of Lake Winnipeg in Northern Manitoba, Canada. With a focus on freeze-up and mid-winter processes, this characterization informed design of a 2D numerical modelling methodology to simulate ice-affected winter hydraulics. Model development included simulation of both thermal and dynamic ice phenomenon, which relied on derivation of numerous site-specific hydraulic functions. The presence of significant skim ice runs in this region inspired development of a novel treatment to simulate freeze-up jamming of skim ice floes on very mild-sloped rivers. The modelling methodology shows strong performance in simulating both freeze-up and mid-winter hydraulics, which is a signficiant contribution considering the complexity of this lake-outlet system. A quantitative evaluation of the effects of climate change on river ice hydraulics is included, with future projection of shorter and warmer winters leading to greater cumulative discharge from Lake Winnipeg. While discharge increases may lead to increased power production in future years, concurrent projections of increased inter-annual variability may present new operational challenges. Findings from this original research can be applied not only to the Nelson River, but also other regulated regions that are impacted by river ice.

Municipal water distribution system (WDS) expansion is often focused on increasing system capacity with designs that best meet hydraulic requirements at the least cost. Increasing public awareness regarding global warming and environmental degradation is making environmental impact an important factor in decision-making for municipalities. There is thus a growing need to consider environmental impacts alongside cost and hydraulic requirements in the expansion and design of WDSs. As a result, the multiplicity of environmental impacts to consider in WDS expansion can complicate the decisions faced by water utilities. For example, a water utility may wish to consider environmental policy issues such as greenhouse gas emissions, non-renewable resource use, and releases to land, water, and air in WDS expansion planning. This thesis outlines a multi-objective optimization approach for WDS design and expansion that balances the objectives of capital cost, annual pumping energy use, and environmental impact minimization, while meeting hydraulic constraints. An environmental impact index that aggregates multiple environmental measures was incorporated as an environmental impact objective function in the multi-objective non-dominated sorting genetic algorithm-II (NSGA-II) optimization algorithm. The environmental impact index was developed to reflect stakeholder prioritization of specific environmental policy issues. The evaluation of the environmental impact index and its application to the WDS expansion problem was demonstrated with a water transmission system example. The environmental impact index and multi-objective non-dominated sorting genetic algorithm-II (NSGA-II) optimization algorithm were applied to the “Anytown” network expansion problem. Preliminary results suggest that solutions obtained with the triple-objective capital cost/energy/EI index optimization minimize a number of environmental impact measures while producing results that are comparable in pumping energy use and, in some instances, slightly higher in capital cost when compared to solutions obtained with a double cost/energy optimization in which environmental impact was not considered.

‘Urban Metabolism’ (UM) is a well-established concept based on the parallels between the metabolisms’ of ecosystems and cities. These parallels consist of the intake, storage, and transformation of materials and energy, and the creation and output of wastes. These traits, which suggest cities possess a metabolism similar to ecosystems, also exist within water distribution systems (WDSs). Four common areas of UM assessments include: the evaluation of environmental sustainability indicators; greenhouse gas accounting; numerical models for the assessment of metabolic flows; and design and decision support tools. These applications show promising opportunities if applied to WDSs, and therefore a novel framework based on UM was developed specifically for the assessment of WDSs. This framework was tested on a water distribution network via three experiments. Experiment 1 utilized factorial design to systematically assess predominate network parameters (water demand, static lift, and pipe roughness). Experiments 2 and 3 studied the effects of two network management strategies (water conservation and pipe replacement scheduling) as well as the effects of static lift and pipe roughness in the presence of these strategies. The results were reported in terms of four metabolic flows: water, operational energy (O/E), embodied energy (E/E), and greenhouse gases (GHGs). Experiment 1 showed that individual increases in water demand, pipe roughness, or static lift, all led to decreases in network pressures and reductions in leakage volume. Experiments 2 and 3 demonstrated increases to leakage volumes and decreases in per capita GHG emissions in the presence of water conservation measures, and decreases in leakage volumes and increases in O/E transmission efficiency in the presence of pipe replacement programs. Experiments 2 and 3 also demonstrated a reduction in network pressures, and a resulting reduction in leakage volumes, due to additional static lift and pipe roughness. Recommendations for future work were made in four specific areas: (1) the expansion of pre-established metabolic flows, (2) the further study of the effects of pressure management under the scenarios studied, (3) the consideration of other urban systems which may benefit from the application of an UM-based assessment, and (4) the assessment of non-hypothetical WDSs using the developed framework.

There is a growing realization among scientists and policy makers that an increased understanding of today's environmental issues requires international collaboration and data synthesis. Meta-analyses have served this role in ecology for more than a decade, but the different experimental methodologies researchers use can limit the strength of the meta-analytic approach. Considering the global nature of many environmental issues, a new collaborative approach, which we call coordinated distributed experiments (CDEs), is needed that will control for both spatial and temporal scale, and that encompasses large geographic ranges. Ecological CDEs, involving standardized, controlled protocols, have the potential to advance our understanding of general principles in ecology and environmental science.

A coupled model was created that linked the mass transport mechanisms of the channel and the Porous Transport Layer of a Proton Exchange Membrane Fuel Cell. A Volume of Fluid solver in the open-source Computational Fluid Dynamics software, openFOAM, was used to model the two-phase flow in the channel. A Pore Network Model designed for Proton Exchange Membrane Fuel Cells and found in literature was implemented into openFOAM to model the two-phase flow in the Porous Transport Layer. The Pore Network Model was recast into a form suitable for the Finite Volume Method used in openFOAM allowing for coupling between these two components. A coupling strategy called Dirichlet-Neumann partitioning was used for pressure on the boundary that separates the two domains. A Neumann boundary condition for pressure was applied in the channel and a Dirichlet boundary condition for pressure was applied in the Pore Network Model. The value of pressure was passed from the channel to the Pore Network iteratively until convergence was achieved. It was determined that the air pressure in the Porous Transport Layer remains constant before breakthrough therefore allowing for the Pore Network Model only to be solved before breakthrough using a linear pressure distribution along the channel boundary to capture the convective effects of the channel. The effects of convection on water transport in the Porous Transport Layer was investigated and the convective effects were significant enough to cause mass conservation violations when the air inlet velocity was altered from 5-10 m/s. It was determined that the domain widths often used in literature are too small to conserve mass and near wall effects permeate towards the domains center. Two common Porous Transport Layer materials were recreated and it was determined that within the expected range of pressure gradients significant movement of water downstream was observed for the SGL10BA material with less significant movement for the Toray090 sample. It was determined that for post-breakthrough simulations water is needed in the channel to properly set the injection velocity. The numerical stability of these post-breakthrough simulations proved to be extremely fragile.