OPUS: Open Ulethbridge Scholarship
Open ULeth Scholarship (OPUS) is the University of Lethbridge's open access research repository. It contains a collection of materials related to research and teaching produced by the academic community.
Self-archiving your research in OPUS is one way to meet Open Access policies of granting agencies. It is important to retain your final, post-peer-reviewed drafts for submission to OPUS, as this is often the only version publishers will allow to be archived. Click here for information on the U of L Open Access Policy.
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Item
Modelling air, ground surface, and permafrost temperature variability across four dissimilar valleys, Yukon, Canada
(Canadian Science Publishing, 2024) Garibaldi, Madeleine C.; Bonnaventure, Philip; Noad, Nick C.; Kochtitzky, Will
Spatial maps of the air and ground thermal regime were generated for four Yukon valleys. The aim was to model air, ground surface, and ground temperature (at fine spatial resolution) using locally measured inverted surface lapse rates (SLR) to better predict temperature along an elevation gradient. These local models were then compared to a regional permafrost probability model, which utilized differing inversion assumptions, as well as circumpolar and national models generated without considering inversions. Overall, permafrost probability in the regional model matched well with the local models where assumptions of treeline and inverted SLRs held true. When normal SLRs were assumed, permafrost presence was overestimated in each valley. This discrepancy was greatest at high elevations where permafrost was predicted to be the coldest and most widespread. However, the difference between valleys was dependent on surface and subsurface characteristics such as higher snow cover, mature forest, or thick organic layers which show a greater disassociation from the air temperature overall. Appropriate characterization of the SLR is essential for accurate predictions of the ground thermal regime’s spatial distribution and permafrost presence. These models also provide a starting point for better predictions of warming in these valleys and other areas subject to inversions of similar magnitudes.
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Modelling permafrost distribution using the temperature at top of permafrost model in the boreal forest environment of Whatì, NT
(Canadian Science Publishing, 2024) Vegter, Scott; Bonnaventure, Philip; Daly, Seamus; Kochtitzky, Will
Current permafrost models in Canadian boreal forests are generally of low spatial resolution as they cover regional or continental scales. This study aims to understand the viability of creating a temperature at the top of permafrost (TTOP) model on a local scale in the boreal wetland environment of Whatì, Northwest Territories from short-term field-collected temperature data. The model utilizes independent variables of vegetation, topographic position index, and elevation, with the dependent variables being ground surface temperature collected from 60 ground temperature nodes and 1.5 m air temperature collected from 10 temperature stations. In doing this, the study investigates the relationship vegetation and disturbance have on ground temperature and permafrost distribution. The model predicts that 31% of the ground is underlain by permafrost, based on a mean annual temperature at TTOP of <0 °C. This model shows an accuracy of 62.5% when compared to cryotic assessment sites (CAS). Most inaccuracies, showing the limitations of the TTOP model, came from peat plateaus that had been burned in the most recent forest fire in 2014. These resulted in out-of-equilibrium permafrost and climatic conditions that TTOP cannot handle well. Commonly, permafrost mapping places Whatì in the extensive discontinuous zone, estimating that between 50% and 90% of the ground is underlain by permafrost. The study shows that a climatically driven TTOP model calibrated with CAS can be used to illustrate ground temperature heterogeneity from short-term data in boreal forest wetland environments. However, this approach likely underestimates permafrost extent and is perhaps not the best-suited modelling choice for near-surface permafrost, which is currently out of equilibrium with the current climate.
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Rock glacier inventory and predictive modeling in the Mackenzie Mountains: predicting rock glacier likelihood with a generalized additive model
(Canadian Science Publishing, 2024) Thiessen, Rabecca; Bonnaventure, Philip; Lapalme, Caitlin M.
Rock glaciers have been the subject of extensive research in recent years due to their potential to serve as indicators of past and present climate conditions and their potential impacts on water resources. Location and descriptive rock glacier data within the Mackenzie Mountains were used to build a rock glacier inventory that will serve as a valuable resource for future research and monitoring efforts. Additionally, this study maps the likelihood of rock glacier presence using extracted variables in a generalized additive model (GAM). The model incorporates attribute data, including potential incoming solar radiation (PISR), topographic position index (TPI), slope, elevation, and lithology as controls for rock glacier development. Topographic data were compiled for three study regions of the Mackenzie Mountains from a 30 m digital elevation model (DEM). The analysis of the GAM showed that the most significant explanatory variables were PISR, elevation, slope, and TPI. The GAM model had an accuracy of 0.87 with a sensitivity of 0.92. This study provides important insights into the controls, distribution, and dynamics of rock glaciers in the Mackenzie Mountains, as well as both the limitations and the potential of statistical models in predicting their occurrence.
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An assessment of provincial policy and youth vaping rates in Alberta
(Lethbridge, Alta. : University of Lethbridge, Faculty of Health Sciences, 2025) Hepp, Amanda; University of Lethbridge. Facutly of Health Sciences; Hallström, Lars
To date, no research has examined the impact of the new youth vaping policy in Alberta
which was implemented July 2021. The purpose of this study was to examine changes in youth
vaping and purchasing patterns in Alberta following the new legislation. Cross-sectional data
collected before and after the policy's implementation were compared. Additionally, differences
between sex, gender, and grade level were evaluated.
Cross-sectional data were obtained through two cycles of the Canadian Student Tobacco
Alcohol and Drugs Survey from students in grades 7 through 12 in 2018/19 and 2021/22 (pooled
n = 15,578). The samples were weighted to represent youth in Alberta in each period. Changes in
vaping prevalence and underage purchases between survey waves were analyzed using
proportions and logistic regression models adjusted for confounders.
In Alberta, there was a 5.1% reduction in the prevalence of youth vaping following 2021
legislation to restrict this activity. The weighed proportion of students who vaped decreased from
19.9% in 2018/19 to 14.8% in 2021/22. After adjustment for confounders, there was a
statistically significant reduction on past 30-day vape use between survey waves (OR: 0.65, 99%
CI: 0.56–0.76). This decrease was more pronounced in males and students in grades 10–12. In
2018/19, 12.6% of youth purchased vape products underage and this slightly increased to 13.3%
in 2021/22, however, these changes, including stratification by sex/gender, were not statistically
significant.
There was a statistically significant decline in youth vaping between survey waves,
particularly among older youth and males, during the introduction of a new prevention policy.
However, unmeasured factors such as societal trends and cultural norms may have also played a
role.
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Muslim immigrant women's experiences of mental health challenges in Southern Alberta, Canada
(Lethbridge, Alta. : University of Lethbridge, Faculty of Health Sciences, 2025) Hosseinpour, Zohreh; Faculty of Health Sciences; Kellett, Peter
The purpose of this study was to explore the experiences of mental health challenges in Muslim immigrant women in Southern Alberta. Exploratory descriptive qualitative research design and semi-structured interviews with ten Muslim women were employed. Thematic analysis of these collected data showed that Muslim immigrant women participants experienced some mental health challenges due the intersection of pre-migration and post-migration factors. To cope with mental health challenges, Muslim women utilized a series of coping mechanisms including seeking professional help. However, some elements such as cultural and religious factors impacted their decisions. The study recommended that stakeholders, policy makers, and mental health professionals provide Muslim immigrant women with culturally safe services to promote their mental well-being.