888 results
Search Results
2. PbIso: an R package and web app for calculating and plotting Pb isotope data.
- Author
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Armistead, Sheree E., Eglington, Bruce M., and Pehrsson, Sally J.
- Subjects
WEB-based user interfaces ,ISOTOPES ,RADIOISOTOPES ,CANADIAN provinces - Abstract
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 (
238 U/204 Pb), time-integrated κ (232 Th/238 U), 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]- Published
- 2024
- Full Text
- View/download PDF
3. Slope risk management in light of uncertainty and environmental variability—2021 Canadian Geotechnical Colloquium.
- Author
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Macciotta, Renato
- Subjects
ROCKFALL ,LANDSLIDES ,CONFERENCES & conventions ,CLIMATE change ,GEOTECHNICAL engineering ,WEATHER - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
4. A review of large-scale renewable energy partnerships with Indigenous communities and organizations in Canada.
- Author
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Yalamala, Reddi Sekhara, Zurba, Melanie, Bullock, Ryan, and Diduck, Alan P.
- Subjects
RENEWABLE energy sources ,CLEAN energy ,INDIGENOUS children ,ECONOMIC development projects ,BUSINESS skills ,ENVIRONMENTAL protection - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
5. Icing and aufeis in cold regions II: consequences and mitigation.
- Author
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Turcotte, B., Dubnick, A., and McKillop, R.
- Subjects
COLD regions ,HYDRAULIC structures ,WATER table ,SPRING ,INFRASTRUCTURE (Economics) ,ICE - Abstract
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]
- Published
- 2024
- Full Text
- View/download PDF
6. A science and management partnership to restore coregonine diversity to the Laurentian Great Lakes.
- Author
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Bunnell, David B., Ackiss, Amanda S., Alofs, Karen M., Brant, Cory O., Bronte, Charles R., Claramunt, Randall M., Dettmers, John M., Honsey, Andrew E., Mandrak, Nicholas E., Muir, Andrew M., Santucci Jr, Victor J., Smith, David R., Strach, Russell M., Sweka, John A., Weidel, Brian C., Mattes, William P., and Newman, Kurt R.
- Subjects
MANAGEMENT science ,ADAPTIVE natural resource management ,FISHERY management ,BIOLOGICAL extinction ,LAKES ,INDIGENOUS fishes ,FRESHWATER biodiversity ,FRESHWATER habitats - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
7. LRFD calibration for soil failure limit state using the Stiffness Method.
- Author
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Bathurst, Richard J. and Allen, Tony M.
- Subjects
LOAD factor design ,FAILED states ,BUILDING foundations ,ROAD construction ,BRIDGE design & construction ,BEARING capacity of soils - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
8. Industrial innovation and infrastructure as drivers of change in the Canadian boreal zone1.
- Author
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Musetta-Lambert, Jordan L., Enanga, Eric M., Teichert, Sonja, Creed, Irena F., Kidd, Karen A., Kreutzweiser, David P., and Sibley, Paul K.
- Subjects
TECHNOLOGICAL innovations ,NATURAL resources ,PAPER pulp ,TAIGAS ,TAIGA ecology ,SOCIAL values ,ECOSYSTEM services ,ELECTRON tube grids - Abstract
Copyright of Environmental Reviews 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.)
- Published
- 2019
- Full Text
- View/download PDF
9. Improvement of tailings impoundment seismic and post-seismic stability using densification and waste rock inclusions.
- Author
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Contreras, Carlos Andrés, Yniesta, Samuel, and Aubertin, Michel
- Subjects
TAILINGS dams ,SURFACE fault ruptures ,METAL tailings ,GROUND motion ,EARTHQUAKES ,NUMERICAL analysis - Abstract
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.)
- Published
- 2023
- Full Text
- View/download PDF
10. Developing a machine learning-based approach for predicting road surface friction using dash camera images—a City of Edmonton, Canada, case study.
- Author
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Xie, Qian and Kwon, Tae J.
- Subjects
MACHINE learning ,PAVEMENTS ,STANDARD deviations ,FRICTION - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
11. Crustal eduction and slab-failure magmatism in an Orosirian (2.05–1.80 Ga) postcollisional cratonic foredeep: geochronology of Seton volcanics and Compton laccoliths, Tu Cho (Great Slave Lake), NWT, Canada.
- Author
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Hoffman, Paul F., Macdonald, Francis A., Bowring, Samuel A., Ramezani, Jahandar, Buchwaldt, Robert, Hildebrand, Robert S., and Whalen, Joseph B.
- Subjects
VOLCANOLOGY ,GEOLOGICAL time scales ,THRUST belts (Geology) ,MAGMATISM ,OROGENIC belts ,VOLCANISM ,LAKES - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
12. Comparison between MERRA-2 and CWEEDS for use in pavement mechanistic-empirical design in Canada.
- Author
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Shafiee, Mohammad, Maadani, Omran, and Cobo, Juan Hiedra
- Subjects
FLEXIBLE pavements ,PAVEMENTS ,PAVEMENT management ,RESILIENT design ,DATA quality - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
13. Canada's maritime frontier: the science legacy of Canada's extended continental shelf mapping for UNCLOS.
- Author
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Mosher, David C., Dickson, Mary-Lynn, Shimeld, John, Jackson, H. Ruth, Oakey, Gordon N., Boggild, Kai, Campbell, D. Calvin, Travaglini, Paola, Rainey, Walta-Anne, Murphy, Alain, Dehler, Sonya, and Ells, John
- Subjects
GEOMORPHOLOGY ,CONTINENTAL shelf ,UNITED Nations Convention on the Law of the Sea (1982) ,GEOSTROPHIC currents ,SUBMARINE fans ,CONTINENTAL slopes ,CONTINENTAL margins - Abstract
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 km
2 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]- Published
- 2023
- Full Text
- View/download PDF
14. Development of quick seismic evaluation procedure for existing buildings in Canada.
- Author
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Fathi-Fazl, Reza, Fazileh, Farrokh, Cai, Zhen, and Cortés-Puentes, W. Leonardo
- Subjects
PILOT projects - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
15. Calibration of resistance factors for design of shallow foundations against sliding.
- Author
-
He, Pengpeng and Fenton, Gordon A.
- Subjects
SHALLOW foundations ,LOAD factor design ,SLIDING mode control ,BEARING capacity of soils ,MONTE Carlo method ,WIND pressure - Abstract
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 ν
ϕ′ = 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]- Published
- 2023
- Full Text
- View/download PDF
16. Tillage effects on growing season nitrous oxide emissions in Canadian cropland soils.
- Author
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Pelster, David E., Matteau, Jean-Pascal, Farrell, Richard, and Hernandez Ramirez, Guillermo
- Subjects
GREENHOUSE gases ,GROWING season ,NITROUS oxide ,TILLAGE ,GREENHOUSE gas mitigation ,TUNDRAS - Abstract
Minimizing tillage has been promoted as an agricultural practice that may mitigate greenhouse gas emissions through carbon sequestration. However, there is some ambiguity regarding the effect of minimum tillage (MT) on emissions of other greenhouse gases, in particular soil nitrous oxide (N
2 O) emissions. To determine how effective MT could be in helping Canada mitigate greenhouse gas emissions, we used a meta-analysis to compare growing season N2 O emissions from MT versus conventional tillage (CT). Overall, MT had 12% lower N2 O emissions compared to CT (P = 0.03). However, there was high variability due to soil texture and growing season precipitation (GSP), with MT tending to emit more N2 O than CT in climates where GSP exceeded 600 mm, particularly for soils with sand content less than 60%. Therefore, unless long-term tillage trials, which are urgently needed in eastern Canada, show a reduction in N2 O emissions over time, MT should be used as a greenhouse gas mitigation measure only in dry climates or on sandy soils. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
17. Crop yields under no-till in Canada: implications for soil organic carbon change.
- Author
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VandenBygaart, A.J. and Liang, B.C.
- Subjects
NO-tillage ,CROP yields ,GREENHOUSE gases ,CARBON in soils ,SOIL classification ,SOIL texture - Abstract
Crop yields directly affect carbon (C) inputs into soils. Tillage management can influence crop performance, and as such should be considered when quantifying soil organic carbon (SOC) change, and thus net greenhouse gas emissions from croplands for national greenhouse gas inventory reporting. We conducted a meta-analysis of the effects of no-tillage (NT) and conventional tillage (CT) on crop yields for multiple crop species, soil types, and climatic regions of Canada. Yield response to NT varied between western and eastern Canada. Regardless of crop type, experiment duration, soil texture, and residue management, experiments in eastern Canada showed an average of 6% lower yields (p ≤ 0.005) under NT compared to CT. In western Canada, crop type had an important effect on yields between NT and CT with wheat, canola, and legumes exhibiting 10% (p ≤ 0.001), 7% (p ≤ 0.05), and 9% (p ≤ 0.05) higher yields on average under NT compared to CT, respectively. In western Canada, higher yields would be reflected in a similar scale of higher C inputs to NT systems. A recent meta-analysis of the effects of tillage management on SOC in Canada showed an 8% higher storage of SOC under NT systems compared to CT, a difference limited to western Canadian soils. Incorporating the effect of tillage on C inputs will lead to improvements in the accuracy of the effects of tillage management on SOC change in Canadian cropland. The activity data can be improved by applying weightings to the yield data by site-specific assessment of tillage practices across Canada. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. An economic review of conservation tillage practices: select case studies from the eastern Prairies of Canada.
- Author
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Khakbazan, M., Carew, R., Crittenden, S., Mohr, R.M., and Biswas, D.K.
- Subjects
NO-tillage ,CONSERVATION tillage ,CANOLA ,CLAY loam soils ,SOIL conservation ,WHEAT ,LOAM soils - Abstract
This study reviewed the literature on soil conservation practices and analyzed four case studies in different soil zones and diverse cropping systems of Manitoba (MB), western Canada, to show the potential impacts of no-till/reduced tillage practices on field crop economic performance. Primary and secondary data, such as tillage type, input cost, crop price, crop yield, and net revenue (NR), were used to assess the tillage practices in each of the case studies. Based on crop economic analysis, over 9 years (1998–2006) in southern Manitoba, cereal-based (spring wheat (Triticum aestivum L.) and barley (Hordeum vulgareL.)) cropping systems were more profitable under conservation tillage than conventional tillage practices, whereas the opposite was true for oilseed crops (e.g., canola, Brassica napus L.). In plot-scale studies at Portage, MB, low intensity tillage increased NR for soybean (Glycine max L.) in 1 of 3 years when compared to high intensity tillage, and there appeared to be lower NRs for canola as tillage intensity increased. However, in studies near Brandon, MB, NRs for a 4-year wheat-pea (Pisum sativum L.) rotation were lower in low disturbance seeding than high disturbance seeding systems for a clay loam soil but similar for a loam soil. While no single tillage system was found to consistently provide the highest NR based on these case studies, these findings provide insights into some of the factors behind decisions surrounding tillage management and the rationale for the continued use of a combination of conventional, reduced, and zero-till systems in the eastern Prairies of Canada. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Review of nonlinear modelling parameters and acceptance criteria in ASCE 41 for seismic evaluation and upgrading of steel structures in Canada.
- Author
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Kim, Taeyong, Kwon, Oh-Sung, Acosta, Joaquín, Fathi-Fazl, Reza, Fazileh, Farrokh, and Cai, Zhen
- Subjects
RETROFITTING of buildings ,STEEL framing - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
20. Undrained capacity of circular shallow foundations on two-layer clays under combined VHMT loading.
- Author
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He, Pengpeng and Newson, Tim
- Subjects
SHALLOW foundations ,BEARING capacity of soils ,FATIGUE limit ,FINITE element method ,CLAY ,SHEAR strength - Abstract
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.)
- Published
- 2022
- Full Text
- View/download PDF
21. Seismic performance assessment of conventional construction concrete moment-resisting frame buildings in Canada using the FEMA P695 methodology.
- Author
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Fazileh, Farrokh, Khosravi, Sadegh, Dolati, Abouzar, Fathi-Fazl, Reza, and Saatcioglu, Murat
- Subjects
CONCRETE construction ,SEISMIC response ,SYSTEM safety ,ARCHETYPES - Abstract
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.)
- Published
- 2022
- Full Text
- View/download PDF
22. Using synthetic climate datasets for geotechnical and geoenvironmental design problems.
- Author
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Bashir, Rashid, Sahi, Muhammad A.N., and Sharma, Jitendra
- Subjects
SWELLING soils ,SOIL infiltration ,CIVIL engineers ,CIVIL engineering ,COMPUTER simulation - Abstract
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.)
- Published
- 2022
- Full Text
- View/download PDF
23. Semi-quantitative seismic risk screening tool for existing buildings in Canada.
- Author
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Fathi-Fazl, Reza, Cai, Zhen, Cortés-Puentes, W. Leonardo, and Fazileh, Farrokh
- Subjects
WEB-based user interfaces ,RESOURCE allocation - Abstract
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.)
- Published
- 2022
- Full Text
- View/download PDF
24. Investigation of climate change impacts on early-age cracking of jointed plain concrete pavements in Canada.
- Author
-
Shafiee, Mohammad and Maadani, Omran
- Subjects
CONCRETE pavements ,CLIMATE change ,ATMOSPHERIC temperature ,ATMOSPHERIC models ,WIND speed ,HUMIDITY - Abstract
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.)
- Published
- 2022
- Full Text
- View/download PDF
25. Field monitoring of the ground vibrations adjacent to an onshore wind turbine foundation.
- Author
-
He, Pengpeng, González-Hurtado, Jesús, Newson, Tim, Hong, Hanping, Postman, Melanie, and Molnar, Sheri
- Subjects
WIND turbines ,SOIL vibration ,PARTICLE motion ,FREQUENCIES of oscillating systems ,WIND power ,STRUCTURAL dynamics ,NEAR-fields ,FLUCTUATIONS (Physics) - Abstract
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.)
- Published
- 2021
- Full Text
- View/download PDF
26. Calibration of resistance factors for geotechnical seismic design.
- Author
-
Naghibi, Farzaneh and Fenton, Gordon A.
- Subjects
EARTHQUAKE resistant design ,SEISMIC testing ,ROAD construction ,BRIDGE design & construction ,SHALLOW foundations ,CALIBRATION ,BRIDGES - Abstract
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.)
- Published
- 2019
- Full Text
- View/download PDF
27. A simplified seismic design method for limited-ductility steel multi-tiered concentrically braced frames in moderate seismic regions.
- Author
-
Derakhshan Houreh, Eshagh and Imanpour, Ali
- Subjects
STEEL framing ,EARTHQUAKE resistant design ,STEEL ,NONLINEAR analysis ,TALL buildings - Abstract
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.)
- Published
- 2022
- Full Text
- View/download PDF
28. Short-term response of soil aggregate stability and labile carbon to contour tillage, diversion terrace, grassed waterway, and tile drainage implementation.
- Author
-
Driscoll, Bryan A., Krzica, Maja, Comeau, Louis-Pierre, Eskelson, Bianca N. I., and Sheng Li
- Subjects
SOIL structure ,TILLAGE ,SOIL degradation ,DRAINAGE ,SOIL stabilization - Abstract
Soil degradation has been of great concern for New Brunswick's potato farmers, especially on sloped land and shallow soils. In this study, we evaluated the initial response of labile soil carbon (C) fractions (permanganate oxidizable C (POXC) and particulate organic C (POC)) and aggregate stability to two integrated best management practices (BMPIs) composed of the following individual practices: diversion terraces (DT), grassed waterways (GW), and contour tillage (CT) (i.e., DTGW) and DT, GW, CT, and tile drainage (TD) (i.e., DTGW + TD), relative to CT that served as a control. The more water was regulated in the field, the greater the increase in labile C; where DTGW and DTGW + TD gained 19.8% and 50.6% of POXC, respectively, while CT lost 11.2% of POXC. There was an increase in mineral associated organic matter C in the terraced BMPIs, despite the high amount of tillage events that took place during potato cultivation. Two BMPIs had no effect on aggregate stability, most likely due to the short duration of this initial monitoring study that spanned just over two growing seasons. Even though there were no improvements in soil structure, our findings showed that some stabilization of soil C is possible even during the initial two seasons following BMPI implementation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. Enhancing unsupervised video-based vehicle tracking and modeling for traffic data collection.
- Author
-
Zaki, Mohamed H., Sayed, Tarek, and Billeh, Moataz
- Subjects
ACQUISITION of data ,VEHICLE models ,TRAFFIC cameras ,CAMCORDERS ,TRAFFIC flow measurement ,ARTIFICIAL satellite tracking ,DATA collection platforms - Abstract
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.)
- Published
- 2020
- Full Text
- View/download PDF
30. Benchmark NBC editions for seismic risk management of existing buildings in Canada.
- Author
-
Fathi-Fazl, Reza, Kadhom, Bessam, Cai, Zhen, and Fazileh, Farrokh
- Subjects
BUILDING operation management ,RISK assessment ,PROVINCES - Abstract
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.)
- Published
- 2021
- Full Text
- View/download PDF
31. Recycled nutrients as a phosphorus source for Canadian organic agriculture: a perspective.
- Author
-
Nicksy, Jessica and Entz, Martin H.
- Subjects
FOOD waste ,PHOSPHATE rock ,PHOSPHORUS ,CROPPING systems ,FERTILIZERS - Abstract
Copyright of Canadian Journal of Soil 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.)
- Published
- 2021
- Full Text
- View/download PDF
32. Ratio of non-growing season to growing season N2O emissions in Canadian croplands: an update to national inventory methodology.
- Author
-
Pelster, David E., Thiagarajan, Arumugam, Liang, Chang, Chantigny, Martin H., Wagner-Riddle, Claudia, Congreves, Kate, Lemke, Reynald, Glenn, Aaron, Tenuta, Mario, Hernandez-Ramirez, Guillermo, Bittman, Shabtai, Hunt, Derek, Owens, Jennifer, and MacDonald, Douglas
- Subjects
GROWING season ,FARMS ,CORRECTION factors ,COLD regions ,AGRICULTURE - Abstract
National inventory reporting of agricultural nitrous oxide (N
2 O) emissions in Canada is based primarily on measurements obtained using static chambers. In regions with cold winters and an accumulated snowpack (including Canada), these measurements tend to focus on the growing season (typically May–October). However, research has shown that emissions continue throughout the non-growing season (NGS) and that these account for a significant proportion of annual emissions. In the Canadian National Inventory NGS emissions currently are assumed to be adequately captured in western Canada, while they are accounted for in eastern Canada by multiplying the growing season emissions by a correction factor of 1.4, a value that was derived based on a limited number of measurements. Here we use recent Canadian studies to validate this correction factor. We collected data from available Canadian studies that measured soil N2 O emissions from agricultural systems for the entire year and determined the proportion of these emissions that occurred during the NGS. The proportion of annual N2 O emissions that occurred during the NGS varied widely, ranging from −4% to 119% with a mean of 35.5%, compared to the previous estimate of 30%. Due to high variability, few differences were observed between means associated with climatic, soil, and management variables. To correct for NGS N2 O emissions from Canadian agricultural soils, we suggest that the current correction factor for converting growing season to total annual emissions be changed from 1.4 to 1.55 and that this be used for all agricultural soils in Canada rather than just eastern Canada. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
33. Do cover crops on the Canadian prairies affect soil nitrogen cycling?
- Author
-
Otchere, O., Lawley, Y., and Congreves, K.A.
- Subjects
COVER crops ,PRAIRIES ,NITROGEN cycle ,NITROGEN in soils ,CROP rotation ,AGRICULTURAL productivity ,RED clover - Abstract
For one of Canada's most important regions of crop production—the prairies—it's uncertain if cover crops can be successfully integrated into rotations; if so, will soil nitrogen (N) cycling be influenced to benefit main crops? To address these gaps, we compared a crop rotation with cover crops (CC) vs. without cover crops (LR) from 2018 to 2021 in Saskatoon, SK. The main crops were grown in sequence of wheat–canola–potato–pea; the cover crops included red clover, berseem clover/oat mix, fall rye, and a brassica cover. Yield and aboveground biomass were collected each year and analyzed to determine crop yield and N use efficiency (NUE). Soil N availability was monitored in various ways, that is, by assessing pre-plant soil nitrate, soil inorganic N (SIN) supply rate, and potentially mineralizable N (PMN). We found that the influence on soil N dynamics was restricted to the non-growing season where cover crops reduced SIN supply rate and nitrate content compared to the conventional practice without cover crops. Yet, rotations with vs. without cover crop did not differ in crop NUEs, yields, or in-season N dynamics. We found some evidence that diversifying rotations with cover crops may help the system to function more like perennial systems in terms of regulating N in the long run; but had limited impact during the three years studied. To ensure that cover crops are effective and functional on the prairies, innovative design approaches are needed to adapt cover crops to reach soil health goals under prairie conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
34. Rationalizing mottling and gleying in the characterization and classification of Canadian soils.
- Author
-
Heck, Richard J., Saurette, Daniel D., and Warren, C. James
- Subjects
SOIL horizons ,SOILS ,SOIL classification - Abstract
Mottling and gleying remain important characteristics for the classification of soils in Canada. The development of criteria for the morphological description of these redoximorphic soil features, for soil horizon nomenclature, for the taxonomy of gleysolic and gleyed soils, as well as for soil drainage classification, began in the mid-1940s and continued for the next four decades. Despite advancements elsewhere, notably with Soil Taxonomy and the World Reference Base, there have been minimal refinements made in Canada, during the past quarter century. Various issues are identified, including the need for more succinct and clearer definitions, a revision of standards for the field characterization of redoximorphic features, as well as more consistency in the application of concepts across existing taxa and systems. A taxonomic framework to more effectively reflect redoximorphic features, such as a new "Redoximorphic Phase" is also discussed. Ultimately, it is recommended that a special committee to be established to conduct a thorough study and present recommendations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Development of ductility-related modification factor for CLT-coupled wall buildings with replaceable shear link coupling beams.
- Author
-
Teweldebrhan, Biniam Tekle, Popovski, Marjan, McFadden, Jasmine B.W., and Tesfamariam, Solomon
- Subjects
GROUND motion ,WALLS ,WOODEN building ,TIMBER - Abstract
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 (R
d ) 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]- Published
- 2023
- Full Text
- View/download PDF
36. Geomorphic diversity of the Newfoundland and Labrador Shelves Bioregion.
- Author
-
Shaw, John, Li, M.Z., and Kostylev, V.E.
- Subjects
CONTINENTAL slopes ,CONTINENTAL shelf ,SEDIMENT transport ,SEDIMENT analysis ,MULTIBEAM mapping - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
37. Climate conditions in the near-term, mid-term and distant future for growing soybeans in Canada.
- Author
-
Qian, Budong, Smith, Ward, Jing, Qi, Kim, Yong Min, Jégo, Guillaume, Grant, Brian, Duguid, Scott, Hester, Ken, and Nelson, Alison
- Subjects
CLIMATE change models ,COMMODITY futures ,CLIMATE extremes ,DROUGHTS ,GLOBAL warming ,SOYBEAN industry ,SOYBEAN - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
38. Decision factors influencing new variety adoption in western Canada by the seed industry.
- Author
-
Lassoued, Rim and Smyth, Stuart J.
- Subjects
SEED industry ,OILSEEDS ,HIGH yield investments ,AGRICULTURE ,FARMERS ,CROP improvement - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
39. Testing cover crop species under three soil moisture conditions in a controlled greenhouse environment.
- Author
-
Ben Kalifa, M.L., VanVolkenburg, H., and Vasseur, L.
- Subjects
COVER crops ,SOIL moisture ,CLIMATE extremes ,EXTREME environments ,SPECIES ,GREENHOUSES ,PEARL millet ,PLANT-water relationships - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
40. Effects of postharvest deficit irrigation on sweet cherry (Prunus avium) in five Okanagan Valley, Canada, orchards: II. Phenology, cold hardiness, fruit yield, and quality.
- Author
-
Houghton, E., Bevandick, K., Neilsen, D., Hannam, K., and Nelson, L.M.
- Subjects
SWEET cherry ,DEFICIT irrigation ,FRUIT yield ,IRRIGATION farming ,ARID regions ,AGRICULTURE - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
41. An update on the seismic categorization for seismic risk assessment of existing Canadian buildings.
- Author
-
Motazedian, Dariush, Fathi-Fazl, Reza, Cai, Zhen, and Fazileh, Farrokh
- Subjects
RISK assessment ,SPECTRAL sensitivity ,TALL buildings - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
42. U–Pb geochronology: its development and importance in Canada.
- Author
-
Davis, Donald W.
- Subjects
LASER ablation inductively coupled plasma mass spectrometry ,SECONDARY ion mass spectrometry ,GEOLOGY ,GEOLOGICAL time scales - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
43. Preliminary investigations of ground failures triggered during the mid-November 2021 atmospheric river event along the southwestern British Columbia highway corridors.
- Author
-
Sepúlveda, Sergio A., Ward, Brent C., Cosman, Scott B., and Jacobs, Rachel
- Subjects
ATMOSPHERIC rivers ,TRANSPORTATION corridors ,LANDSLIDES ,CLIMATE extremes ,RIPARIAN areas ,ROADS ,CLIMATE change - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
44. Resilience-based optimization model for maintenance and rehabilitation of pavement networks in a freeze–thaw environment.
- Author
-
Mohammed, Ahmed, Abu-Samra, Soliman, Zayed, Tarek, Bagchi, Ashutosh, and Nasiri, Fuzhan
- Subjects
PAVEMENTS ,PAVEMENT management ,ASSET management ,MATHEMATICAL models ,REHABILITATION ,INVENTORY shortages - Abstract
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.)
- Published
- 2021
- Full Text
- View/download PDF
45. Methodology for seismic risk screening of existing buildings in Canada: Structural scoring system.
- Author
-
Fathi-Fazl, Reza, Cai, Zhen, Jacques, Eric, and Cortés-Puentes, W. Leonardo
- Subjects
EARTHQUAKE resistant design ,DESIGN services - Abstract
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.)
- Published
- 2021
- Full Text
- View/download PDF
46. Roughness prediction models using pavement surface distresses in different Canadian climatic regions.
- Author
-
Patrick, Graeme and Soliman, Haithem
- Subjects
PAVEMENTS ,PREDICTION models - Abstract
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.)
- Published
- 2019
- Full Text
- View/download PDF
47. Material properties for fracture mechanics based strength assessment of cast iron water mains.
- Author
-
Debnath, Suborno, Ali, Ismail M., Dhar, Ashutosh Sutra, and Thodi, Premkumar
- Subjects
FRACTURE mechanics ,CAST-iron ,MECHANICAL properties of condensed matter ,WATER-pipes ,NOTCH effect ,FRACTURE toughness - Abstract
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.)
- Published
- 2021
- Full Text
- View/download PDF
48. Scientific considerations and challenges for addressing cumulative effects in forest landscapes in Canada.
- Author
-
Venier, L.A., Walton, R., and Brandt, J.P.
- Subjects
ECOLOGICAL disturbances ,NATURAL resources ,DATA integration ,LANDSCAPES ,ACQUISITION of data ,FORESTS & forestry ,FOREST management - Abstract
Copyright of Environmental Reviews 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.)
- Published
- 2021
- Full Text
- View/download PDF
49. The first rolling load simulator (ROLLS) for testing bridges in Canada and its application on a full-scale precast box girder.
- Author
-
Fam, Amir and Brennan, Dustin
- Subjects
BOX beams ,BRIDGE testing ,CONCRETE beams ,ROAD construction ,BRIDGE design & construction ,BRIDGES - Abstract
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.)
- Published
- 2020
- Full Text
- View/download PDF
50. Integration of perennial forage seed crops for cropping systems resiliency in the Peace River region of western Canada.
- Author
-
Khanal, Nityananda
- Subjects
SEED crops ,CROPPING systems ,AGRICULTURAL intensification ,SOIL biodiversity ,AGRICULTURAL pests ,HERBICIDE-resistant crops ,CROP rotation - Abstract
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]
- Published
- 2023
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