Grad Research Day

November 21, 2016

Grad Research Day this year will be Monday, Nov 21 starting at 10am in RCB 6152. This is a great opportunity to find out what kind of exciting research our students are up to, and to provide helpful feedback.

  • Date: Nov 21, 2016
  • Time: 10am - 4pm
  • Room: RCB 6152

Here's the brief description for each presentation.

10:00am              Eric Cao

Program: MSc
Supervisor: Jeremy Venditti

“Evolution of Bedrock Canyons in Response to Plunging Flow.”

Erosion in bedrock river facilitates the formation of canyons and topographical relief. The rate of erosion can be calculated using erosion models with the assumption of uniform flow. However, existing models might not be applicable in bedrock canyons, where plunging flows occur in response to lateral constrictions. This study aims to determine the erosion rate in bedrock canyons through flume experiments and compare with model predictions; as well as examine the initiation and evolution of canyon morphology under the plunging flow condition.

10:30am              Jeff Morgan

Program: MA
Supervisor: Valorie Crooks

“Healthcare mobility and the outsourcing of medical education.”

International healthcare mobility involves the movement of patients, practitioners, and trainees across borders to facilitate medical care. Increasingly, Canadians are choosing to study medicine abroad, many enrolling in private institutions in the Caribbean know as offshore medical schools. Offshore medical schools are for-profit enterprises that provide undergraduate medical education to students primarily from the US and Canada who wish to return home to practice medicine. This study uses qualitative interviews with Canadian medical school administrators and representatives from professional associations to learn more about the impacts of these institutions on the Canadian healthcare and medical education systems, with a particular focus on quality, accountability, and equity.

11:00am              Ian Lochhead

Program: MSc
Supervisor: Nick Hedley

“Enhancing risk management in complex institutional spaces using 3D data, 3D analyses and 3D visualization interfaces.”

Careful preparation and implementation of emergency management protocols increases an institutions ability to manage risk, respond to disasters, and build resilience so that they can recover in a timely manner.  Yet emergency management is often neglected, or at least overlooked, due to a lack of knowledge, an overdose of apathy, or insufficient resources.   Geographic information systems (GIS) and advanced 3D analytical geovisual technologies provide an opportunity to simulate and explore multiple emergency scenarios, while systematically testing emergency plans without the temporal and capital overhead associated with real world emergency drills.  Spatial analytical 3D virtual environments (VE) enable new ways to explore, understand and experience digital simulations of hazardous scenarios that would be too dangerous in the real world – this might be to understand lethal drop zones for building debris, or to ‘run with the bulls’ and become a virtual observer embedded within the crush of panicked evacuating crowds.  This research will explore the use of conventional 2D and 3D GIS, and advanced 3D geovisual interfaces for emergency management at SFU’s Burnaby campus.

11:30am              Kurt Frei

Program: MSc
Supervisor: Lance Lesack

“Fire-driven selection and function of stream wood in sub-boreal conifer forest ecosystems of central Interior British Columbia.”

Wood strongly influences stream ecology. Research of stream wood recruitment following wildfire has been key in forecasting stream ecosystem structure but the selection of individual trees in becoming stream wood following wildfire is poorly understood, as is the functionality of fire-recruited wood that bridges streams. I sampled 18 reaches of small (<3 m wide) streams in Entiako Provincial Park, British Columbia, two years after the Chelaslie fire that burned in 2014 and roughly 10 years following an epidemic of native bark beetles. To address the effect of tree characteristics on likelihood of recruitment and stream functionality I measured stream wood loads, shaded cover, streambed light levels, and riparian forest stand structure. Here, I present preliminary results from analyses of stream wood recruitment. I will use multiple regression and generalized linear models to estimate the probability of tree fall into streams following riparian fires based on forest stand structure. This research aims to increase our understanding of the influence of wildfire occurrence on key determinants of freshwater ecosystem structure.

12:00pm              Aateka Shashank

Program: MA
Supervisor: Nadine Schuurman

“Measuring walkability: a methodological study.”

Background: Walkability research is a crossing of two disciplines, urban planning and health, that studies the ability of the built environment to support healthy physical activity. With the improvement of mapping software and technologies, walkability research has proliferated. However, different understandings of the built environment and their subsequent ontologies permeate research methodologies. The focus of this paper is to explore these methodological differences through the entire research process of creating a walkability index.

Methods: First, we address ontological and methodological differences in current walkability literature. Second, we assess ontologies of connectivity, a proxy of walkability, ranging from measures of intersection density, link-node ratio, to street block length using data from Surrey, Canada. Finally, we recreate three commonly used indices using data from Vancouver, Canada.

Results: A comparison of 10 measures of connectivity reveals extreme variance in resulting connectivity scores for neighbourhoods in Surrey. However, measures of link-node ratio remain consistent for many neighbourhoods in Surrey. The comparison of the three indices also reveals variance in the resulting walkability scores for neighbourhoods in Vancouver.

Conclusion: Following suit with literature on place effects on health, we conclude that context specific measures of the built environment require assessment and careful consideration of variables chosen to represent walkability. This study encourages researchers studying the relationship between the built environment and health to remain cognizant of ontological differences that can affect data collection, data interroperability, and the interpretation of resulting scores.

Lunch 12:30-1:30

1:30PM                Margaret Valerio

Program: MSc
Supervisor: Kirsten Zickfeld

“Exploring the Relationship Between Vertical Mixing, Overturning Circulation, and AABW Volume During the Last Glacial Maximum”

During the Last Glacial Maximum (LGM), the deep ocean is understood to have stored roughly 70­-90ppm of atmospheric CO2. Ocean circulation changes likely contributed to the ocean's increased ability to store carbon. In the Atlantic Ocean, North Atlantic Deep Water (NADW) likely shoaled by at least 1000m, while Antarctic Bottom Water (AABW) expanded below 2000m. AABW is also thought to have become poorly ventilated during the LGM, making it a stronger reservoir for carbon. Both paleo­environmental data and arguments for a strengthening of the biological pump during glacial periods support a weakening of overturning circulation, yet few modelling efforts have been able to reduce overturning while simulating AABW volume growth. One theory for this discrepancy is that a mechanism may be missing from models, whereby mixing between AABW and NADW reduces as the boundary between the two water masses shoals, either from increased stratification or increased distance from bottom topography. If so, upwelling would be reduced, allowing AABW to increase in volume without the need for increased overturning. This research addresses the relationship between vertical mixing, AABW volume, and overturning circulation using the UVic Earth System Climate Model with four different mixing parameterizations. The parameterizations include constant vertical diffusivity, a standard Bryan and Lewis scheme, a custom linearized version of the Bryan and Lewis scheme, and a tidal mixing scheme. The linearized Bryan and Lewis scheme is inspired by a topographically based mixing scheme of De Boer and Hogg (2014), which was able to increase AABW volume and residence time while decreasing overturning circulation in a 3­box model. The overturning circulation and water mass distribution will be analyzed and compared between model versions with different mixing schemes under both glacial and modern boundary conditions.

2:00pm                Xinru Li

Program: MSc
Supervisor: Kirsten Zickfeld

“Exploring the reversibility of changes in ocean conditions under net-negative CO2 emissions.”

Artificial carbon dioxide removal (CDR) from the atmosphere, also referred to as “negative CO2 emissions”, has been proposed as a measure of mitigating climate change and restoring the climate system to a state that avoids ‘dangerous’ impacts. Previous studies have demonstrated that the changes in surface air temperature due to anthropogenic CO2 emissions can be reversed to some extent through net-negative emissions, while some of oceanic properties, for example thermosteric sea level rise, show a delay in their response to net-negative emissions. This suggests that the artificial removal of CO2 from the atmosphere might be ineffective in reversing climate changes in components of the climate system with long (>100 years) response timescales. This research aims to investigate the reversibility of ocean conditions after the implementation of artificial carbon removal on centennial timescales. This objective is achieved by exploring the multi-century responses of the climate system to a set of emission scenarios with a focus on ocean biogeochemical properties. We use RCP2.6 and its extension until year 2300 as the reference scenario and design a set of overshoot scenarios based on other RCPs. The University of Victoria Earth System Climate Model (UVic ESCM), a climate model of intermediate complexity, is forced with these emission scenarios. We compare the responses of select ocean variables in the overshoot emission scenarios to that in the reference scenario at the time the same amount of cumulative emissions is achieved. Furthermore, we investigate whether the degree of reversibility is dependent on the level of overshoot. With the focus on seawater pH, aragonite saturation, temperature and dissolved oxygen, we find that the overshoot and subsequent return to a reference CO2 cumulative emissions level would leave substantial impacts on the marine environment.

2:30pm                Mitchell Bergstresser

Program: MSc
Supervisor: Lance Lesack

“Microbial methane cycling in Mackenzie Delta Lakes: Comparing microbial community diversity and activity with environmental parameters.”

Methane, a potent greenhouse gas, is also a substantial source of carbon and energy for ecosystems within Arctic lakes.  Complex communities of microbes in the water column and sediment in these lakes play an important role in the production and consumption of methane.  The Mackenzie River Delta in Canada's Northwest Territories is the largest river system in Canada, the second largest floodplain system in the circumpolar Arctic region and contributes substantially to the global methane budget.  The microbial communities in these lakes, and the different environmental factors that influence their community structure and activity levels, have not been studied before in this system. My project aims to characterize the structure and activity of methane-cycling microbial communities in the water and sediment of a variety of lakes to better understand the dynamics of methane cycling and microbial life in the Mackenzie River Delta.

3:00pm                Rebeca Salas

Program: MA
Supervisor: Nick Blomley

“Spatial Narratives of Property Loss: A Geographical Perspective on the Relationship Between Memory and Property.”

In partnership with the Landscapes of Injustice SSHRC-Funded research project (LoI), this project provides a critical geographic dimension to an emergent literature on property and memory.  Memories of property loss and displacement reveal that there are under-recognized values and meanings attached to property ownership.  I draw from LoI’s Oral Histories to consider the question:  How are social memories of property loss spatialized?  Research participants have first-hand or second-hand memories of Japanese Canadian property dispossession, displacement, and reestablishment during WWII.  I use two frames to navigate the data: “citizenship” and “investment” (of labour, love, and relationships), which represent under-recognized values or meanings of property.  I argue that memories of property loss and displacement are haunted in particular sites of memory and that these spatialized memories are closely tied to “citizenship” and “investment”.  However, data coding reveals that each generation recalls, understands, and prioritizes these values differently.  To address and honour intergenerational differences, I compare archival narratives from the time of uprooting to participants’ memories of injustice.