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The paper describes load and resistance factor design (LRFD) calibration for the resistance factor used in the Stiffness Method internal stability soil failure limit state for geogrid mechanically stabilized earth (MSE) walls. The Stiffness Method was recently adopted in the current American Association of State Highway and Transportation Officials LRFD Bridge Design Specifications in the US, and will appear in the next edition of the Canadian Highway Bridge Design Code. The paper describes the details of the calibration of the soil failure limit state which is unique to the Stiffness Method. Calibration outcomes include consideration of the concept of level of understanding in the selection of nominal load and resistance values which is unique to LRFD foundation engineering practice in Canada. A practical conclusion from these calculations is that if product line-specific creep test data are available to estimate the reinforcement secant creep stiffness used for design, then a resistance factor of 1.0 is reasonable for US practice. If only minimum average roll value tensile strength data are available, then a value of 0.95 is recommended for US practice. For Canadian practice, the corresponding values for typical level of understanding are 0.90 and 0.85, respectively. [ABSTRACT FROM AUTHOR]

This paper investigates the possibilities and challenges of using mass timber as a sustainable alternative for retrofitting existing buildings in Canada. To create the knowledge foundation on which to devise a holistic framework tailored to the specific characteristics of Canada's built environment, a detailed analysis of the types, geographical distribution, structural, and energy features of the local building stock is first presented. Then, previous strategies for enhancing and upgrading existing buildings with engineered timber are reviewed, classified, and evaluated. Finally, to explore economic and environmental implications, a detailed assessment of available life-cycle cost–benefit analysis approaches is conducted alongside their adaptation to Canada's building context. The findings of this paper can inform policymakers, builders, and designers in developing more sustainable building retrofit practices, design, and regulations, in line with Canada's efforts toward net zero emissions. [ABSTRACT FROM AUTHOR]

The package PbIso is a free and open R toolbox for commonly used calculations and plots of Pb–Pb isotope data and for generating Pb evolution models. In this paper, we review Pb isotope systematics and the calculations that are commonly used, such as model age, model source μ (238U/204Pb), time-integrated κ (232Th/238U), and initial Pb isotope ratios. These equations are implemented into R functions in the package PbIso. In addition, functions are provided for generating Pb evolution models, paleoisochrons, and isochrons. This allows users to apply calculations to their data in a straightforward way while providing transparency and flexibility of the calculations used. We have implemented some basic features of the PbIso package into an online shiny R application (see https://shereearmistead.github.io/software/pbiso), which makes it easy for users without any R experience to use these calculations with their own data and to generate plots. We have provided a case study from the Superior Province in Canada, showing how different Pb evolution models can be generated in PbIso and compared to Pb isotope data. [ABSTRACT FROM AUTHOR]

Landslides are common across Canada and they pose hazards to human safety, economic activities, and the environment. Robust risk management strategies are necessary for sustainable development. A slope risk management framework has been adopted by the geotechnical community for approximately four decades allowing a systematic, consistent and transparent framework for managing risks. Implementing this framework is associated with uncertainties embedded in our estimates of risk. This paper presents a brief summary of the sources and categories of uncertainty in geotechnical slope engineering and focuses on two topics: (1) estimates of uncertainty in risk calculations and (2) temporal changes in landslide likelihood as a function of weather and steps towards estimating landslide risk changes with climate change. The paper argues that a quantitative risk assessment should not focus on the final risk calculation, but the overall knowledge gained. This allows comprehensive documentation of sources of uncertainty and how they impact geotechnical and risk assessments. Furthermore, the paper outlines approaches to define quantitative correlations between rock fall occurrences and weather, which can be leveraged to estimate changes in rock fall risk with climate change. The paper corresponds to, and expands on, the 2021 Canadian Geotechnical Colloquium. [ABSTRACT FROM AUTHOR]

Canada ratified the United Nations Convention on the Law of the Sea (UNCLOS) in 2003. With that ratification is an obligation to submit data and information to the U.N. pertaining to the limits of the country's extended continental shelf (ECS); the portion of the juridical continental shelf that extends beyond 200 nautical miles. A team of Canadian scientists, managers, and legal experts that included representation from three Federal Departments (Natural Resources Canada, Fisheries and Oceans Canada, and Global Affairs Canada) with additional support from other departments, spent 13 years compiling and acquiring data to provide the scientific evidence to support delineation of Canada's seaward most maritime limit. The submission has the potential to provide Canada with 2.4 million km2 of additional submarine landmass in the Atlantic and the Arctic oceans over which Canada exercises sovereign rights for the purpose of exploring and exploiting its natural resources. Specific information such as the tectonic framework of the continental margin, the geomorphology of the margin and in particular the continental slope, the geologic nature of adjoined ridges, rises, and plateaux, and sediment thickness within adjacent basins are examples of fundamental pieces of geoscientific information needed to substantiate Canada's outermost maritime limits. This paper highlights a number of segments of Canada's continental margins to showcase this scientific evidence and how it is applied in the UNCLOS context. In doing so, the paper demonstrates the geologic complexity of Canada's margins as illustrated in scientific publications that have resulted from these new data collections, while at the same time presenting new scientific evidence and interpretations. This collection of data and information provides a wealth of new knowledge in Canada's offshore regions. The massive data compilation in the Atlantic led to conception of continental margins, in a source-to-sink scenario, as having an equilibrium base level or graded form, comparable to river systems. Departures from this shape relate to the interplay of sedimentary processes and in particular to those processes that do not fit the source-to-sink paradigm. For example, a significant part of the Atlantic margin is shown to be heavily influenced by along-slope geostrophic currents that generated massive contourite drift deposits. These deposits reflect lateral transport of sediment that had a significant impact on the morphology of the margin. The role of mass transport processes in shaping continental margins is also highlighted, and in particular the collapses of entire segments of the margin were observed. The prominent role mass failure processes play in delivering sediment to the adjacent abyssal plain is also critical in the ECS context. These observations challenge the entrenched notion of a continental margin comprising a shelf, slope, and rise and in particular the concept of the "continental rise". Prior to 2006, regions of the Arctic Ocean seaward of the Canadian landmass had fewer than 5000 km of seismic reflection data. The massive efforts of Arctic coastal States to map their margins for ECS purposes have led to a leap in technological advances to acquire data in ice-covered seas and have led to a wealth of new geoscientific knowledge. Perhaps foremost amongst this knowledge is demonstration that Canada Basin is indeed a fully developed ocean basin, albeit significantly infilled with sediment. Based on this knowledge and identification of related structures, new realistic tectonic scenarios for opening of the Amerasia Basin are proposed that include a significant component of transform or strike-slip motions. With seismic velocity and rock sample information, the continental nature of Alpha and Mendeleev ridges has been substantiated. Even bathymetric data were lacking in the Arctic and new editions of seafloor maps now support grids of 500 m spacing; although some regions remain sparse. Once thought to be relatively stagnant, sedimentary processes such as found in many ocean basins were discovered in the Arctic Ocean. Evidence of geostrophic currents, sediment mass failures, and deep-sea turbidity current channels were found to be ubiquitous, even in the deepest parts of the Arctic's basins. [ABSTRACT FROM AUTHOR]

In this paper, a review of Indigenous engagement in renewable energy projects is conducted and the main elements of energy partnerships between stakeholders and Indigenous partners are discussed. In recent years, Canada has witnessed more significant Indigenous involvement in economic and energy development projects than ever before. For large-scale energy partnerships, the focus is on engagement, financial capital, community buy-in (readiness, and entrepreneurial and business skills), and benefits-sharing with community partners. Equity-ownership, reconciliation, and self-determination intersect with and impact the benefits and sustainability of energy projects, as they are interrelated in the framework of most energy partnerships. This paper illustrates policy disconnects in connection with partnership-making, social outcomes, and decision-making among Indigenous communities. Furthermore, findings from relevant literature explore the nuanced discourse on social implications and capacity challenges that interlink with climate adaptation and reconciliation when promoting large-scale renewable energy partnerships with Indigenous communities. Through a systematic review and a meta-analysis of the literature, we found 80 relevant studies during the screening process, of which 33 were selected for the synthesis. Findings demonstrate that the Crown, energy companies, and community partners need to coordinate and collaborate closely to achieve energy security and sustainable renewable energy. The review suggests that Indigenous engagement in energy partnerships supports positive outcomes for social development and environmental protection among Indigenous communities. The literature suggests that when government and industry mentor in the project implementation process, important positive impacts on energy transitions, and self-sufficiency can be realized. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The seismic resilience of structures can be quantified through rigorous seismic assessment. Because no detailed guideline is available for nonlinear modelling parameters and the corresponding acceptance criteria for the seismic evaluation and upgrading of steel structures in Canada, the structural commentary of the National Building Code of Canada suggests using ASCE 41, which has been adopted as a standard for seismic evaluation and retrofit of buildings in the United States (U.S.). However, because the steel design standards in Canada and the U.S. are different, their applicability to steel structures in Canada needs to be investigated. To this end, this paper critically reviews the nonlinear modelling parameters and acceptance criteria, and then recommends whether these values need to be revised or are adopted as is for the seismic evaluation and upgrading of steel structures in Canada. A numerical example of a steel moment-resisting frame is presented to demonstrate the recommended parameters being used for seismic evaluation. [ABSTRACT FROM AUTHOR]

The National Research Council Canada (NRC) is currently developing seismic evaluation and upgrading guidelines for existing buildings in Canada. The seismic evaluation guidelines consist of three tiers of seismic evaluation procedures, that is, Tier 1 Quick Evaluation, Tier 2 Deficiency-Based Evaluation, and Tier 3 Detailed Evaluation. This paper presents the Tier 1 Quick Evaluation procedure, which aims to update the initial quick evaluation procedure in the existing seismic evaluation guidelines developed by the NRC in early 1990s. The proposed procedure covers seismic assessment of both structural and non-structural elements, and requires the review of construction documents, on-site inspection, and calculations. A set of checklists are contained to uncover potential key seismic deficiencies of the building under evaluation. The checklists are in the form of evaluation statements that relate to potential seismic deficiencies in the structural systems and non-structural components. The proposed procedure is demonstrated by conducting the seismic evaluation of an existing building that is part of a pilot study. [ABSTRACT FROM AUTHOR]

The design of shallow foundations typically proceeds by using the load and resistance factor design (LRFD) methodology to avoid various limit states with some probability. This paper looks at the sliding limit state of shallow foundations, and the sliding resistance factors required for the LRFD approach are estimated using reliability analyses of surface strip foundations. Cohesive and frictional soils are separately studied under wind loading conditions. Monte Carlo simulations are used to estimate the sliding failure probability of foundation designs on cohesive soils, and an analytical method is developed for frictional soils. The results indicate the existence of a "worst case" correlation length for cohesive soils, and the sliding resistance factor required to achieve target maximum lifetime failure probabilities is around 0.4–0.65 for moderate soil variability. For frictional soils, the required sliding resistance factor is about 0.5–0.85 for νϕ′ = 0.15. Overall, the sliding resistance factors recommended here agree well with the resistance factors of ϕgu = 0.6 for cohesive soils and ϕgu = 0.8 for frictional soils stipulated by geotechnical LRFD code provisions in Canada. The analyses can be used to estimate the reliability of current designs and can also aid the calibration of geotechnical design codes. [ABSTRACT FROM AUTHOR]

The process of icing and the resulting layered ice masses, called aufeis, are caused by the freezing of overflow originating from groundwater or surface water. Aufeis can directly impact infrastructure and property, most commonly through winter ice formation and spring flooding within, against, and on the surface of hydraulic structures and transportation infrastructure. They also represent a safety concern for drivers. This geohazard often needs to be managed proactively and efficiently to mitigate associated risks. This paper provides an overview of the consequences of aufeis in northwestern Canada. A total of 50 existing and novel icing and aufeis mitigation approaches are described and classified. The context of applicability for each approach is identified, considering the source of water, the type of infrastructure, and its role in the formation of aufeis. Finally, future research avenues to support the development or improvement of aufeis risk reduction techniques are presented. [ABSTRACT FROM AUTHOR]

Similar to many freshwater ecosystems, the Laurentian Great Lakes of North America have undergone numerous anthropogenic stressors resulting in considerable loss of biodiversity and habitat. Among Great Lakes fishes, the coregonine sub-family has endured the most extensive declines, including extinction of several species (Coregonus johannae, C. alpenae, and C. kiyi orientalis) and at least 10 instances of local extirpations of other species (C. nigripinnis, C. reighardi, C. zenithicus, C. hoyi, and C. artedi) across all 5 lakes, much of which occurred prior to the 1960s owing to overfishing, interactions with non-indigenous species, and habitat loss. Despite these declines, no federal-, provincial-, or state-mandated actions were ever implemented to conserve coregonine diversity, potentially because so much of the coregonine declines occurred prior to the enactment of federal conservation legislation. Possible explanations for inaction since enactment of that legislation include insufficient data on biological vulnerability or threats, unresolved taxonomy, and limited support from the fishery management agencies and their stakeholders prior to the 2000s. In recent decades, however, several fishery management agencies have undertaken efforts to re-introduce coregonine diversity. These efforts helped lead to development of a science-based framework to restore coregonines that was universally endorsed by fishery managers representing eight U.S. states, four U.S. tribal organizations, and the province of ON, Canada, in May 2018. The basin-wide framework is based on principles of conservation biology and adaptive management. We describe details of its key steps, including planning, restoring, and evaluating, while also describing recent implementation efforts to develop methods, improve available resources, and enhance coordination across the basin. Although our paper describes a regional effort to restore native coregonines, our adaptive-management approach could be used by other multi-agency stakeholders seeking to conserve or restore native fishes. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tailings impoundments are often prone to failure due to various causes related to complex loading conditions. For instance, tailings impoundments can fail during or after a seismic event, mainly because of the liquefaction of loose, cohesionless tailings. To improve the seismic stability of impoundments, the density of the tailings can be increased or waste rock inclusions (WRI) can be added in the impoundment. This paper presents the results of numerical analyses of the impoundments loaded with a variety of ground motions with different frequencies, scaled at two different levels of intensity representative of two mining regions of Eastern Canada. The results show that the conventional impoundments are subjected to medium to high displacements at the end of shaking; these show a high probability of rupture during the earthquake or in the post-seismic phase. Tailings densification can decrease the volume of liquefied tailings and displacements during the seismic phase but does not significantly reduce the probability of post-seismic failure. WRI can slightly reduce the volume of liquefied tailings, depending on the intensity of the motions, but the reinforcement reduces significantly the lateral displacements; impoundments with WRI show even better performances during the post-seismic phase. The use of WRI is deemed a good approach to ensure the seismic stability of tailings impoundments and reduce the risk of seismically induced failure. [ABSTRACT FROM AUTHOR]

Although road surface friction is considered the most effective performance measure for maintenance operations, it is not commonly used due to the high cost of collection. As a result, most jurisdictions use subjective visual indicators that qualitatively describe the state of the road surface, even though they create measurement inconsistencies and offer less detailed maintenance tracking. For maintenance personnel to transition into using friction, the collection cost must be reduced. This paper attempts to do so by proposing a low-cost, machine learning-based method for predicting road surface friction using dash camera imagery and demonstrates its feasibility through a case study. The dataset used for this project was collected in the City of Edmonton, AB, Canada during its 2021/2022 winter season. Three models were developed using tree-based algorithms, where all three displayed high performance with an average root mean squared error of 0.0796 or 79.3% accuracy based on RMSPE. [ABSTRACT FROM AUTHOR]

Three Orosirian basins and associated foreland thrust-fold belts are preserved on the margins of the Slave craton. All three are related to orogenic belts where oceans opened and later closed, uniting new crustal partners. The Great Slave basin differs from the Kilhigok and Coronation basins in ways that have defied explanation. It lacks a passive margin sequence and hosts two discrete igneous suites, separated by large-scale thrusting, that occurred well after the adjacent paleocean had closed. Here we report U–Pb zircon geochronology by chemical abrasion isotope dilution thermal ionization mass spectrometry for a member of each suite to constrain the age and origin of postcollisional thrusting. A widespread pulse of mainly phreatic alkaline volcanism, coeval with renewed foredeep flexure, occurred at 1889.0 ± 0.7 Ma (2σ internal error). A quartz-monzodiorite body, one of a belt-parallel chain of laccoliths that postdate thrusting, was emplaced at 1866.9 ± 0.9 Ma. These ages bracket renewed foredeep sedimentation and thrusting that telescoped major facies zones and was rooted within the basin. The older age is 70 and 30−60 Myr younger than collision in the Thelon and Taltson orogens, respectively. We attribute postcollisional thrusting and foredeep subsidence to "eduction"—the upward and outward ejection of partly subducted crust—and postulate that the top of the ejected wedge was a normal-sense detachment fault projecting beneath the Nonacho basin. We infer that eduction was triggered by slab failure, producing alkaline volcanism, and ended with delamination and laccolith emplacement. Eduction was facilitated by tradewind-driven erosion. Delamination was enabled by crustal transfer to the educted wedge, reducing footwall buoyancy. Slab failure and/or delamination removed the passive margin. [ABSTRACT FROM AUTHOR]

To improve the climate resiliency of existing and new pavements, it is important to carry out pavement designs using continuous climate records at high temporal frequencies. Over the years, significant research efforts have been dedicated to obtain high-quality climatic data for pavement design including the latest adoption of the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2). The purpose of this study is to assess how MERRA-2 performs when compared to the Canadian Weather Energy and Engineering Datasets (CWEEDS), which provides hourly meteorological data for many parts of the country from various periods. In the first part, climate parameters at nine locations were directly compared to determine the correlation between two data sets. In the second part, long-term performances were simulated for typical flexible pavement to assess the relative impact of each climate scenario. As detailed in this paper, observed differences between MERRA-2 and CWEEDS indicate the need for further improvement of climate data quality and availability for designing resilient pavements in Canada. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Public transit plays a significant role in the sustainability of an urban region which requires high pedestrian safety at the interchange points. This research studies the magnitude of pedestrian collisions in the proximity of Public Transit Access Points (PTAPs) and address how Traffic Calming strategies and road elements improve pedestrian safety at PTAPs. Getis-Ord Hotspot Analysis and the Negative Binomial models are applied to address research questions. Pedestrian collisions occur more frequently at intersections with the presence of a PTAP and with a higher volume and number of bus routes. Traffic calming strategies such as road width reduction, sidewalk width increase, median refugees, pedestrian crossing phase, and vehicle stop signs could improve pedestrian safety of PTAP. Besides, pedestrians are at more risk in PTAP at locations where high road gradients and in proximity to intersections with a higher number of directions of vehicle traffic flow. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Laird Lake property, southwest Red Lake greenstone belt, straddles the contact between the Balmer (2.99–2.96 Ga) and the Confederation (2.74–2.73 Ga) assemblages. The property is 10 km along strike from the Madsen and Starrat–Olsen Au mines that are hosted near the contact. The Balmer assemblage consists of fine-grained, aphyric, locally pillowed mafic volcanic rocks, ultramafic intrusive and volcanic rocks with flow breccia textures hosting local spinifex-bearing clasts, and banded-iron formations. In contrast, the Confederation assemblage comprises porphyritic mafic volcanic rocks intercalated with intermediate to felsic volcanic rocks that include crystal lapilli tuffs, crystal tuffs, and tuffs. The Balmer assemblage is composed of tholeiitic mafic volcanic rocks with minor Al-undepleted komatiites, whereas the Confederation assemblage is calc–alkalic. Neodymium isotopes, in conjunction with trace element geochemistry, suggests that parts of the Balmer assemblage were weakly contaminated by an older intermediate basement. Both arc and back-arc volcanism occurs in the Confederation assemblage, with the arc rocks showing a stronger crustal component than the back-arc rocks. A maximum U–Pb age of 2741 ± 19 Ma for a crystal tuff and an age of 2737.68 ± 0.79 Ma for a diorite are consistent with a Confederation assemblage affinity for the intermediate calc–alkaline rocks south of the Au-bearing horizon. The Balmer assemblage represents an oceanic plateau formed by plume magmatism on the margins of the North Caribou Terrane, whereas the Confederation assemblage at Laird Lake formed in an oceanic arc setting where both arc and back-arc volcanism occurred simultaneously. [ABSTRACT FROM AUTHOR]

Several countries are planning to safely contain and isolate used nuclear fuel in a deep geologic repository. Similar to other countries, Canada's Nuclear Waste Management Organization (NWMO) proposes to place used fuel in corrosion-resistant containers deep underground as part of a multiple barrier approach. Key components of the sealing systems are bentonite-based and must maintain low hydraulic conductivity and an ability to swell when in contact with free groundwater. Swelling pressure (Ps) and hydraulic conductivity (k) data for the specific bentonite product known as MX80 bentonite under low (<15 g/L) through high (>325 g/L) total dissolved solids' (TDS) pore fluids that simulate groundwaters that could be encountered in sedimentary and crystalline rock geospheres are reviewed, and information from ongoing NWMO studies of behaviour is presented. These data are statistically evaluated to establish the best-fit and prediction limit relationships between compacted dry density and Ps and k as they are influenced by porefluid composition. They also allow identification of dry density and(or) TDS (salinity) conditions where Ps and k may not meet defined performance. From these analyses, it is expected that bentonite can be placed such that on achieving fluid saturation and density equilibration, it meets the requirements set for placement room fill. [ABSTRACT FROM AUTHOR]

The objective of this literature review was to compile research findings on climate change and its impacts on crop production in Prairie Provinces of Canada. Our search strategy included finding primary literature articles from various databases. Seven articles reported increases in average and minimum air temperature over time in the Prairie Provinces of Canada. Increases in maximum air temperature were smaller than that forminimum air temperature. Growing degree days and corn heat units also increased over time, which has allowed for potential expansion of corn growth northwards. While overall increases in average annual precipitation and growing season precipitation have occurred in Canada between 1900 and 2021, western Canada showed increases in some regions but decreases in others. Off-season precipitation and snow cover duration in Canada have decreased since 1950. The number of frost-free days has increased across Canada, on the Prairies and southern Saskatchewan since 1900. Annual snowfall has decreased since 1950 and across Canada the annual maximum snow depth has also decreased. Overall, studies focusing on the Prairie Provinces in Canada have shown accelerated changes in several climate parameters over time, affecting cropping areas and crop yields. [ABSTRACT FROM AUTHOR]

Environmental impact assessments (EIAs) aim to assess the predicted effects of future projects on the environment, human health, and the economic potential of a region. They are an instrumental tool for sustainable development and to reduce the impact of large-scale industrial projects on biodiversity. The accurate assessment of the effects of projects on wildlife populations has a variety of ecological, cultural, and economic implications. However, assessments are commonly done using indirect indicators such as the predicted impact of changes in the quantity and quality of wildlife habitat and (or) predicted changes in nonspecific wildlife population metrics (e.g., relative abundance). In recent decades, the interpretation of wildlife health has moved from the classical dichotomous state of "disease presence/absence" to a broader concept that integrates the interaction of biological, social, and environmental health determinants. We sought to determine how wildlife health metrics are used in EIA processes and propose a framework to characterize, quantify, and monitor wildlife health in future EIAs. First, we performed a targeted review of EIA documents from three jurisdictions in Canada to characterize the relevance and use of "wildlife health" in these documents. Then, we reviewed case studies and research examples to understand wildlife health in different contexts associated with conservation biology to propose a framework to incorporate wildlife health into baseline monitoring and mitigation processes in EIAs. Our targeted review illustrates that while wildlife health and related terminology is often invoked in the main and specific objectives of EIAs, it is rarely tracked and quantified in EIAs and related processes. We identified approaches that can be used to effectively incorporate wildlife health in EIAs, including context-specific wildlife health metrics, participatory epidemiology, community-based sampling, and local ecological knowledge. We illustrate case studies where wildlife health can facilitate the inclusion of communities, Indigenous governments, and local ecological knowledge into the evaluation process of projects and developments and into comanagement practices of wildlife. Our work highlights the critical need to move towards incorporating wildlife health into EIA processes to provide a more direct and holistic perspective on the potential environmental impacts and improve the opportunities for early implementation of mitigation measurements. [ABSTRACT FROM AUTHOR]

Dispersants, a class of chemical spill-treating agents used to treat oil spills, are commonly used globally as an alternative response measure. Applying dispersants to an oil slick, shortly after the spill has occurred, can protect shoreline environments and sea surface-dwelling animals, such as some marine bird species, limiting individuals or local populations from the consequences of coming into contact with large quantities of oil. However, this benefit comes with the cost of increasing oil exposure risk to marine biota that spend time in the water column. It is generally believed that the benefits of dispersant use outweigh the costs under most circumstances. However, it is rarely acknowledged that the use of dispersants may have negative impacts on marine biota at the individual or local population level, including marine birds. In Canada, Corexit EC9500A, a regulated dispersant, is being proposed for expanded use beyond treating spills from an offshore oil and gas facility. To understand what the potential impacts from dispersant use are to marine birds, we conducted a literature review to identify the direct and indirect effects of their use. We also provide oil spill responders with a Pathway of Effects (POE) conceptual model, a tool for understanding the interactions between dispersants, marine birds, and their environment to support a holistic consideration as part of the oil spill response decision-making process. Fundamental uncertainties remain, however, and if left unaccounted for in the decision-making process, they may compromise the appropriateness of spill response approaches and outcomes. We recommend that oil spill responders incorporate the known benefits and costs of dispersant use on marine birds into a decision-making framework such as a Net Environmental Benefit Analysis (NEBA) and with consideration of the POE concept models provided. These recommendations are particularly relevant where a decision-making framework such as NEBA is becoming a more standardized component of the response process. Additionally, greater investment in lab and field-based research, and field observations through monitoring, is required to address existing decision-making uncertainties and provide information gap closure. [ABSTRACT FROM AUTHOR]

This study investigated a new predictive model of the shear modulus reduction ( G G max − Log (γ c)) and damping ratio (ξ − Log (γc)) curves for sensitive eastern Canada clays. The model was established based on experimental measurements of G G max and ξ performed on 69 sensitive clay specimens from eastern Canada. The compiled database was first analyzed to qualitatively assess the influences of different soil parameters on the measurements. Next, statistical analyses using regression analysis and the modified hyperbolic model were performed. It was found that the G G max and ξ values of sensitive eastern Canada clays were influenced mainly by the plasticity index (Ip), mean effective stress (σ m ′) , and structure, which was quantified by the liquidity index (IL). Based on the statistical analysis performed, new equations for G G max and ξ were proposed. The newly proposed model was compared with previously published models. The comparison clearly showed that the proposed model was more representative of sensitive eastern Canada clays. Consequently, it is suggested that the proposed model is more appropriate for use in the dynamic analysis of sensitive eastern Canada clay deposits as well as other similar soils. [ABSTRACT FROM AUTHOR]

The desire of using sustainable materials has reignited the interest in timber-based construction. Researchers and practitioners are developing novel timber-based structural solutions. Cross-laminated timber (CLT)-coupled wall is a recently proposed system for potential use in mid- and high-rise timber construction. The National Building Code of Canada, however, does not include this system and, consequently, the seismic force modification factors are not available. This study evaluated the ductility-related force modification factor (Rd) using the FEMA P-695 procedure. Nine archetype buildings were designed considering different design parameters: building storey height, CLT wall configuration, and coupling ratios. Using 30 ground motion records (bi-directional), rigorously selected for seismicity of Vancouver, BC, Canada, incremental dynamic analyses were performed. Collapse margin ratios were calculated to assess the adequacy of the trial Rd factors. Using an over-strength factor of 1.5, Rd = 4 is found to be acceptable for this system. [ABSTRACT FROM AUTHOR]

The Newfoundland and Labrador Shelves Bioregion, located on the glaciated continental shelf and adjacent continental slope of eastern Canada, is classified into units that reflect its great physiographic diversity. There are ten shelf units: bedrock zone, fjord systems, major inlet, shelf-crossing troughs, four types of offshore banks, basin, and disturbed (glaciotectonic) terrain. There are three units on the continental slope: channelized areas, trough-mouth areas, and large sedimentary drifts. A series of vignettes illustrates both the distinguishing characteristics of the principal geomorphic units and the morphologic diversity within them. A sediment mobility analysis reveals that wave- and current-generated disturbances are dominant and largely depth-controlled within the shelf units, while the south-flowing Labrador Current impacts sediment transport and mobility along the continental slope. [ABSTRACT FROM AUTHOR]

The soybean industry in Canada aimed to extensively expand soybean production to benefit from new early-maturing varieties and the warming climate. However, setbacks in the soybean industry since 2017 demonstrated the impacts of climate risk and global market uncertainty. Therefore, a better understanding of future climate conditions that will impact soybean growth in Canada is needed for decision-making in the sector, such as prioritizing regions for expansion and developing climate change adaptation strategies through either agronomic management practices or breeding new cultivars. Based on climate projections from a set of global climate models, we analyzed climate conditions for growing soybeans, including growing season start, crop heat units, precipitation, precipitation deficits and climate extremes, in the near-term (2030s), the mid-term (2050s) and the distant future (2070s). We found that a future warmer climate with an increase of 1.6, 2.8 and 4.1 °C in the growing season (May–September) mean temperature averaged over Canada's land area in the near-term, mid-term and distant future under SSP3-7.0 would favour the expansion of soybean production further north and west. However, an increase of approximately 200 mm in precipitation deficits on the semiarid Canadian Prairies in the mid-term would constrain soybean production unless irrigation could be introduced. Heat- and drought-tolerant cultivars should be developed to adapt soybean production to a changing climate, in addition to the adoption of late-maturing cultivars that would benefit from the lengthened growing season and increased crop heat units. [ABSTRACT FROM AUTHOR]

In the agricultural sector, innovation is a vital economic driver for increasing food production. New crop varieties are developed and commercialized, greatly contributing to improved global food security through higher yields, improved nutrition and climate resiliency. Canada is a competitive and innovative actor in the global seed market. This article quantifies the degree of improvement for numerous crop traits required for commercialization success. We use empirical data from seed producers in the prairies to identify their adoption criteria to multiply new seed varieties. Results show that yield potential, disease resistance and lodging resistance are the key traits for pedigreed seed growers regardless of crop type, while other agronomic traits depend on the crop type. Quality factors such as malting or milling properties for cereals, protein content for pulses and oil content for oilseeds are also part of the variety selection decision process for prairie pedigreed seed growers. [ABSTRACT FROM AUTHOR]

Irrigated agriculture in semi-arid regions is expected to increase in the future, which puts greater demands on scarce water resources. Sustainable irrigation strategies in semi-arid regions will support agricultural resilience to climatic change. The response of "Sweetheart"/Mazzard sweet cherry trees (Prunus avium L.) to postharvest deficit irrigation (PDI), as a water conservation method, was studied over three seasons (2019–2022) in the semi-arid Okanagan Valley of British Columbia, at five commercial orchards. The following irrigation treatments were applied; (i) a control of full irrigation, irrigated according to conventional growers' practice at each orchard, (ii) PDI-30: 27%–33% reduction in irrigation volume, after harvest (67%–73% of control), and (iii) PDI-50: 47%–52% reduction in irrigation volume, after harvest (48–53% of control). Spring phenology (the timing of flower bud development, from side green to full bloom), flower bud moisture content and cold hardiness, and fruit yield and quality (before and after cold storage and shelf-life conditions) were assessed to determine if PDI altered fruit development over the subsequent growing season. Neither PDI-30 nor PDI-50 caused changes in the timing of flower bud phenology, cold hardiness or moisture content relative to the control. PDI treatments also had no effect on fruit yield or fruit quality at harvest or after storage and shelf-life conditions. These results suggest PDI could be used to reduce irrigation water use in semi-arid regions, like the Okanagan Valley, without affecting sweet cherry production or fruit quality. [ABSTRACT FROM AUTHOR]

Extreme climatic events, such as drought and heavy rainfall, are increasing with climate change. These events can threaten agroecosystems, including vineyards. Cover crops are often grown in vineyards for various reasons and can be an effective strategy for climate change adaptation. Understanding which cover crop species can establish well under extreme climate conditions is important. We conducted a greenhouse experiment to investigate the responses of nine cover crop species to overwatered and water-deficit conditions. Treatments included (1) overwatered soil condition, watered at 100% field capacity daily, (2) control, watered at 60%–70% every other day, and (3) water deficit, watered at 15%–20% weekly for 53 growing days. Results indicated that the total dry weight of all species decreased (most significantly) under water-deficit conditions. However, pubescent wheatgrass and red fescue did not exhibit any stress symptoms. Apart from alfalfa, all species established well under overwatered conditions despite slight yellowing of foliage for crimson clover and hairy vetch. Pearl millet and yellow sweet clover had the best establishment regardless of conditions. Our results provide important information on the selection of cover crops that can withstand climatic variability and thrive in the extreme conditions linked to the climate change scenario in Canada. [ABSTRACT FROM AUTHOR]

An investigation has been done to update key input parameters in the recent seismic-risk-screening tools developed by the National Research Council Canada for the six seismic categories. In this study, the seismic categorization system in the recent seismic-risk-screening tools of the National Research Council Canada is extended to include Canadian buildings abroad by including threshold peak ground acceleration values, a more global set of modified Mercalli intensity, peak ground acceleration, and spectral response acceleration and peak ground acceleration relationships. The relationships among spectral response acceleration, peak ground acceleration, and peak ground velocity values have been derived using least-squares regression analyses to obtain the threshold values of both peak values associated with various modified Mercalli intensity values for each seismic category. Based on the updated relationships, the seismic categorization system is applied to 679 locations in Canada and 226 locations outside Canada. [ABSTRACT FROM AUTHOR]

This article presents a history of the development of U–Pb geochronology with emphasis on the role of Canadian researchers and some of its applications to Canadian geology. Modern U–Pb dating is the result of work by many individuals over the past 60 years, but the most important was Tom Krogh, who established methods that allowed determination of precise ages (<0.1% errors) on zircon using isotope dilution thermal ionization mass spectrometry. This was followed by the introduction of new analytical approaches by others, notably secondary ion mass spectrometry and laser ablation inductively coupled plasma mass spectrometry that allow intracrystal domains to be dated. U–Pb geochronology is now an indispensable tool for understanding the Earth. In collaboration with field mapping, it has vastly improved our understanding of the geological history of Canada as well as important geological events such as mass extinctions, secular changes in geological processes, and the birth of the solar system. [ABSTRACT FROM AUTHOR]

An unusually intense atmospheric river affected the southern coastal region of British Columbia in mid-November 2021. Flooding and several ground failures such as landslides and riverbank erosion caused significant damage and interrupted the main transportation corridors, including major highways and railroads, severing land connectivity between Metro Vancouver and the rest of Canada. In this short note, we summarize and describe slope and riverbank ground failures in the Lower Mainland and connecting corridors to the interior such as the Fraser Canyon and the Coquihalla Valley, with focus on those that produced damage on highways. Field observations are discussed in the context of potential future similar disasters in the region due to more frequent extreme climatic events associated with climate change. [ABSTRACT FROM AUTHOR]

The Peace River region is one of the northern agricultural frontiers in Canada, undergoing farmland expansion as well as intensification with input-intensive industrial agriculture. The cropping systems evolved with the rotations between annual grain and perennial forage crops as a prudent adaptation to fragile, crust-forming, runoff-prone, poorly developed, platy-structured acidic Luvisolic soils. In recent years, there is a decline in the acreage of perennial forage seed crops leading to simplified low-diversity cropping systems with heavy reliance on external inputs. The production systems have been prone to the rapid evolution of herbicide-resistant weeds, and outbreaks of crop diseases and insect pests in the face of global warming. A number of studies conducted in the Peace River region and other parts of North America have shown multiple benefits of integrating perennial forage crops in the cropping systems. By virtue of high root-to-shoot ratio and perennial growth, forage seed crops can provide multiple ecological services in the fragile Luvisolic soil through increased soil organic matter, carbon sequestration, soil biological diversity, soil structural improvement, nutrient mobilization, crop protection and environmental health, thereby creating conducive effects to the resilient performance of the cropping systems. This review discusses the merits of crop rotations in general and those of perennial forage seed crops in particular in the face of changing climate, with special reference to studies conducted in the Prairies and Peace region of western Canada. Research opportunities are highlighted to elucidate multidimensional ecosystem services from diversified cropping sequences integrating perennial forage seed crops. Au Canada, la région de la rivière de la Paix marque une des limites les plus nordiques de l'agriculture. Les terres arables continuent de s'y étendre et l'agriculture industrielle s'y intensifie grâce à l'usage massif d'intrants. Les systèmes culturaux ont évolué et la prudence a voulu qu'on adopte des assolements annuels de céréales et de plantes fourragères vivaces en raison de la fragilité du sol, constitué de luvisols acides, mal développés, à structure lamellaire, qui forment des croûtes et sont sensibles au ruissellement. Depuis quelques années cependant, on assiste à une diminution de la superficie consacrée à la production de graines de plantes fourragères vivaces et à l'avènement de systèmes culturaux plus simples, moins diversifiés, qui reposent lourdement sur l'apport externe d'intrants. Avec le réchauffement climatique, pareils systèmes favorisent l'apparition rapide d'adventices résistantes aux herbicides, mais aussi de maladies et d'infestations de ravageurs. Plusieurs études réalisées dans la région de la rivière de la Paix et ailleurs en Amérique du Nord ont illustré les nombreux avantages de l'intégration de plantes fourragères vivaces aux systèmes culturaux. En raison de leur rapport racines:pousses élevé et de leur caractère vivace, les cultures grainières de plantes fourragères pourraient améliorer de diverses manières l'écologie fragile des luvisols (hausse de la quantité de matière organique, séquestration du carbone, diversité de la biologie du sol, amélioration de la structure du sol, mobilisation des éléments nutritifs, protection des cultures, vitalité de l'environnement), ce qui rendrait les cultures plus résilientes. Les auteurs examinent les avantages de l'assolement en général et des assolements de culture grainière de plantes fourragères en particulier face au changement climatique, en faisant spécialement référence aux études réalisées dans les Prairies et la région de la rivière de la Paix, dans l'Ouest canadien. Ils signalent les possibilités de recherche qui permettraient d'élucider les services multidimensionnels à l'écosystème attribuables à la diversité des séquences culturales qui intègrent la production des graines de plantes fourragères vivaces. [Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Stormwater quality management is essential for the protection of aquatic life of receiving waterbodies. This study presents a unique case study, whereby a stormwater management model (SWMM) was developed to assess the performances of street sweeping and infiltration trenches to reduce total suspended solids (TSS) loads in the Town of Jasper located in Jasper National Park, AB, Canada. Two catchment models were developed for the Town using long-term meteorological data, as well as watershed and drainage system data provided by the Municipality of Jasper. The quality parameters were calibrated so that TSS loads at the outfalls were within a 20% error of monitoring data. The performance of proposed best management practices was assessed using single-event and continuous data simulations. The results indicated that a combined sweeping/trench control scenario would generate the highest TSS removal efficiency of up to 51%. [ABSTRACT FROM AUTHOR]

The design provisions for internal glass fiber-reinforced polymer (GFRP) reinforced concrete (RC) columns have been recently under consideration by design committees in Canada and around the world due to new advancements in understanding the behavior of GFRP-RC columns. The slenderness limit is a critical design parameter differentiating between the first- and second-order analyses of GFRP-RC columns. The existing slenderness limits in design standards were calibrated using deterministic approaches. In this study, a novel reliability-based approach was utilized to quantify the reliability index associated with the slenderness limit to calibrate and propose optimized reliability-based slenderness limits for CSA S806 and CSA S6, for the first time. The method takes the advantage of artificial intelligence and incorporates a comprehensive experimental database. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Canadian Journal of Animal Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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