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Effective winter road maintenance relies on precise road friction estimation. Machine learning (ML) models have shown significant promise in this; however, their inherent complexity makes understanding their inner workings challenging. This paper addresses this issue by conducting a comparative analysis of road friction estimation models using four ML methods, including regression tree, random forest, eXtreme Gradient Boosting (XGBoost), and support vector regression (SVR). We then employ the SHapley Additive exPlanations (SHAP) explainable artificial intelligence (AI) to enhance model interpretability. Our analysis on an Alberta dataset reveals that the XGBoost model performs best with an accuracy of 91.39%. The SHAP analysis illustrates the logical relationships between predictor features and friction within all three tree-based models, but it also uncovers inconsistencies within the SVR model, potentially attributed to insufficient feature interactions. Thus, this paper not only showcase the role of explainable AI in improving the ML interpretability of models for road friction estimation, but also provides practical insights that could improve winter road maintenance decisions. [ABSTRACT FROM AUTHOR]

Basal gravel and sand mantling the bedrock floors of buried valleys throughout the Canadian Interior Plains, and conformably overlying proglacial lacustrine sediment, comprise the Empress Group. While previously conceptualized as stratigraphically equivalent deposits of preglacial rivers prior to the first and most extensive continental and montane glaciations, subsequent stratigraphic studies indicated that buried valley basal gravel must have been deposited between, or during, progressively more extensive continental glaciations and could not be stratigraphically equivalent throughout the buried valley network. However, in the general absence of formation-rank stratigraphic description of basal gravel units that might better inform the geologic history of the deposits, most workers simply consider Empress Group sediments time-transgressive. In this paper, we examine basal gravel at provincial and regional scales to understand its genesis and geologic history. At the provincial scale, we map basal gravel in three dimensions using a novel machine learning approach. At the regional scale, we formally define basal gravel formations at either end of the largest buried valley system in Alberta, which informs its glacial history and physiographic development and shows the importance of formation-rank stratigraphic description. Our results indicate that the buried valley network across Alberta is palimpsest in genesis and basal gravel units within it are chronostratigraphically intercalated between tills. We advocate that the Empress Group definition be extended across Alberta with modifications to improve its clarity and utility, and formally define the Old Fort, Unchaga, Ipiatik, and Winefred formations as part of the Empress Group. [ABSTRACT FROM AUTHOR]

Construction crew productivity is affected by the motivation of the crew performing given activities and by situational/contextual factors forming the dynamic construction environment. The literature lacks a comprehensive analysis of causal relationships between crew motivation and situational/contextual factors for dynamic modelling of crew productivity. The contributions of this paper are (1) identifying a set of criteria for performing expert weight assignment for heterogenous group experts in productivity research, (2) proposing an integrated fuzzy analytic hierarchy process–fuzzy decision-making trial and evaluation laboratory approach that provides a systematic, structured method for determining causal relationship mapping between factors affecting crew productivity, and (3) proposing an approach for identifying cause-and-effect groups among the situational/contextual factors and crew motivation, which can further be used to formulate strategic productivity improvement solutions. The proposed methodology is demonstrated using a case study on an actual industrial construction project in Alberta, Canada. [ABSTRACT FROM AUTHOR]

The selection of Architect/Engineer (A/E) is one of the critical decisions made by owners early in a project. Given that architects and engineers are not commodities; therefore, the assessment of A/E firms should be based on their qualifications. This paper attempts to quantitatively assess and understand the effects of A/E capabilities on project performance. To achieve this, a model was developed to identify the correlations between A/E consultant qualification, project characteristics, and project outcomes. Afterwards, it was validated using a prediction model developed using artificial neural networks implemented on a case study of 18 projects. This model connects the gap between the consultant procurement decision and its impact on the management performance and outcomes of a project. Furthermore, this paper offers an understanding of current procurement practices, as well as presenting the common evaluation criteria and their respective weights as adopted by several public owners in Alberta. [ABSTRACT FROM AUTHOR]

The Eocene to Miocene Cypress Hills Formation (CHF) spans 28 million years and forms the conglomeratic caprock of the Cypress Hills and Swift Current plateaus in southwestern Saskatchewan and southeastern Alberta. These stacked fluvial, floodplain, and lacustrine deposits preserve the only high latitude, non-polar mammalian fossil assemblage (Uintan to Hemingfordian land mammal stages) in Canada. The Quarry is the oldest CHF (Chadronian 1, late Eocene) site documented in the Cypress Hills region north of the town of Eastend. The Quarry was originally discovered in 1962, after bones were found to be eroding out of the base of a road cut north of the ghost town of South Fork on the southeastern flanks of the Cypress Hills. Numerous field campaigns have resulted in the collection of fossils from a multitaxonomic bonebed. This paper presents a detailed sedimentologic, paleontologic, and taphonomic study to establish a depositional environment framework of the Southfork Quarry. This site was deposited at the onset of the Eocene–Oligocene climate transition, a critical time of climate change during the Paleogene. Six facies and two facies associations are characterized for the Quarry, shifting from a braided-fluvial system to a debris flow-filled incised channel. Patterns of skeletal accumulations and bone surface modification indicate that the assemblage accumulated over a significant interval of time in different depositional environments. This study provides critical insight into environmental shifts driven by climate change and relates these findings to a broader understanding of the Eocene–Oligocene transition in North America. [ABSTRACT FROM AUTHOR]

Walleye (Sander vitreus) populations in Alberta, Canada, collapsed by the mid-1990s and were a case study in the paper Canada's Recreational Fisheries: The Invisible Collapse? Here we fit age-structured population dynamics models to data from a landscape-scale monitoring program to assess walleye population status and reconstruct recruitment dynamics following the invisible collapse. Assessments indicated that populations featured low Fmsy values of approximately 0.2–0.3 under conservative assumptions for the stock–recruitment relationship but that many populations were lightly exploited during 2000–2018. Recruitment reconstructions showed that recovery from collapse in 33/55 lakes was driven in part by large positive recruitment anomalies that occurred during 1998–2002. Additionally, 15/55 lakes demonstrated cyclic recruitment dynamics. The documented recruitment anomalies and cyclic fluctuations could be due to environmental effect(s) or cannibalism, and experimentation is likely necessary to resolve this uncertainty. These findings contribute new information on the recovery dynamics of walleye following the invisible collapse and demonstrate the effectiveness of coupling traditional fisheries science models with broad-scale monitoring data to improve understanding of population dynamics and sustainability across landscapes. [ABSTRACT FROM AUTHOR]

Regional and global biodiversity may be underestimated due to the presence of cryptic species: species that are morphologically similar, but genetically distinct. Here, we focus on two cryptic duckweed species, Lemna minor L. and Lemna turionifera Landolt, which have overlapping geographic ranges and are easily mistaken for one another. We developed species-specific primers based on DNA barcoding sequences to facilitate the rapid identification of these two monomorphic duckweeds, allowing us to investigate their presence and distribution in Alberta, Canada. While current reports indicate the presence of L. turionifera (and the morphologically distinct Lemna trisulca L.) in Alberta, our data indicate that L. minor is also present, predominantly in the southern part of the province. Thus, this paper (i) contributes to the accuracy and completeness of a regional flora, and (ii) provides useful and flexible tools for the rapid molecular identification of cryptic Lemna species, which are of wide interest in diverse fields such as biotechnology, toxicology, bioremediation, and ecology. [ABSTRACT FROM AUTHOR]

For sheer complexity, braincases are generally considered anatomically conservative. However, recent research on the braincases of tyrannosaurids have revealed extensive morphological variations. This line of inquiry has its root in Dale Russell's review of tyrannosaurids in which he established Daspletosaurus torosus — a large tyrannosaurine from the Campanian of southern Alberta. In the wake of systematic revisions to tyrannosaurines previously assigned to Daspletosaurus, one potentially distinct species remains undescribed. This paper describes and compares a braincase referable to this species with that of the holotype for Daspletosaurustorosus using computerized-tomography-based reconstructions. The two braincases have numerous differences externally and internally. The specimen of Daspletosaurus sp. has a bottlenecked olfactory tract, short and vertical lagena, and a developed ascending column of the anterior tympanic recess. The holotype of Daspletosaurus torosus has many unusual traits, including an anteriorly positioned trochlear root, elongate common carotid canal, distinct chamber of the basisphenoid recess, asymmetry in the internal basipterygoid aperture, and laterally reduced but medially expanded subcondylar recess. This comparison also identified characters that potentially unite the two species of Daspletosaurus, including deep midbrain flexures in the endocasts. However, many character variations in the braincases are known in other tyrannosaurids to correlate with body size and maturity, or represent individual variations. Therefore, taxonomic and phylogenetic signals can be isolated from background variations in a more comprehensive approach by using additional specimens. New information on the two braincases of Daspletosaurus is consistent with the emerging view of tyrannosaurid braincases as highly variable, ontogenetically dynamic character complexes. [ABSTRACT FROM AUTHOR]

To facilitate more efficient winter maintenance decision support, road weather information systems (RWIS) have been widely used by highway agencies. However, the cost of RWIS stations is high, and they have limited monitoring coverage. To address this challenge, this paper presents an innovative framework that applies regression kriging to integrate stationary and mobile RWIS data to improve the accuracy of road surface temperature (RST) estimation. Furthermore, an optimal RWIS network expansion strategy is introduced by incorporating a modified particle swarm optimization method with the objective of minimizing spatially averaged kriging estimation errors. A sensitivity analysis is also conducted to investigate the influence of station densities on model performance. The case study from Alberta, Canada, demonstrates the feasibility and applicability of the proposed method. The findings provide insights for continuous monitoring and visualization of both road weather and surface conditions and for optimizing RWIS network planning. [ABSTRACT FROM AUTHOR]

Construction professionals agree that building information modelling (BIM) will revolutionize the architectural, engineering, and construction (AEC) industry and its impact will be felt by all project stakeholders including owners and facility managers. Statistics show that many owners and other stakeholders perceive BIM as a technology that can make project delivery more efficient because it allows project information to be fully integrated. In the future, owners are expected to demand the use of BIM to prevent over-budget and over-time project delivery. However, as we are preparing this contribution the level of implementation and use of BIM varies widely across the globe. This paper probes the state of BIM in Alberta from three points of view: ( i) the current understanding and implementation, ( ii) the motivations driving its use, and ( iii) the challenges hindering its implementation. The findings of this paper are extracted from individual responses to a web-based survey that was proposed to professionals in the Albertan AEC/FM industries. [ABSTRACT FROM AUTHOR]

Any process that causes a sudden brittle failure of material has the potential to cause earthquake-like seismic events. Cryoseisms represent an underreported class of seismic event due to their (often) small magnitudes. In this paper, we document the phenomenon of some of the largest magnitude lake-associated icequakes (ML 2.0) yet reported. These events occurred nearly simultaneously (within ∼2 h) on geographically separate lakes in Alberta, Canada, starting 1 January 2018. We conjecture that these events were caused by the sudden brittle failure of lake ice due to thermal expansion; the effects of the thermal expansion were compounded by the lack of insulating snow cover, high lake water levels, and a rapid onset of atmospheric warming. These factors also contributed to ice-jacking — a repeating process in which thermal contraction produces tensile cracks (leads) in lake ice that are then filled with water that is frozen during the cooling cycle. Thus, any subsequent thermal expansion must be accommodated by new deformation or brittle failure. This ice-jacking process caused creeping ground deformation after the initial brittle failure and again two weeks later following a second warming period. In many cases, the resulting ground deformation was significant enough to cause property damage. [ABSTRACT FROM AUTHOR]

This paper intends to establish a foundation that will permit an in-depth understanding of absenteeism in large-scale industrial construction. This type of construction currently suffers greatly from the negative impacts (e.g., productivity loss; cost and schedule overruns) of absenteeism. Taking into account the complexity of large-scale industrial construction (e.g., the long operational periods and the tremendous variety of trades and positions involved), a more systematic and comprehensive understanding of absenteeism is necessary. In an effort to address this issue, we developed a survey and an absenteeism tracking tool, both of which can be used in other industrial projects. To test their validity, a pilot project was established in an industrial multi-contractor enterprise in Alberta. The results of this project reveal the great potential of both the survey and tracking tool - it is evident that they can be applied to diverse industrial projects and enable an in-depth understanding of absenteeism. Further, the results have led to several findings (e.g., a significant amount of absences are not reported to supervisors in advance; the need to educate apprentices to avoid absences; and the fact that employees believe that fellow employees are more likely to be absent than themselves). The effects of different absence reduction and compensation policies currently practiced in industrial construction are also discussed in this paper. [ABSTRACT FROM AUTHOR]

A recent study on construction productivity improvement at the University of Calgary revealed the direct tool time (working time) of Alberta’s commercial construction to be about 51%. This study exposed inadequate communication and unavailability of required information as the main causes for a relatively lower tool time. Use of information technology (IT) to overcome widely visible communication issues was extremely limited at the construction site level. Construction companies’ hesitation to adopt new technologies was well noted whereas construction workers expressed their willingness and ability to use IT at the site level. The objective of this paper is to discuss the concept and the application of a novel communication tool (called an information booth) developed and pilot tested at a construction project. The concept and the technology presented in this paper have been tested at an actual construction project resulting in improvements in construction productivity, worker satisfaction, and efficiency. This paper also elaborates the rationale for a new technological framework (and the information booth), barriers for technology implementation, research objectives, methodology, and data analysis. [ABSTRACT FROM AUTHOR]

As the industrial construction sector in Alberta faces a period of megaprojects, cost and schedule overruns are becoming a major concern for both owners and contractors. One factor that often contributes significantly to these overruns is construction field rework. Despite the significance of rework, there are few industry standards available for defining, quantifying, and classifying field rework. This paper presents the results of a pilot study, conducted on one such megaproject, that attempts to develop a standard definition of construction field rework, a standard index for its quantification, and an approach for classifying the causes that lead to field rework so that they can be remedied. The data collection methodology developed is discussed, and the findings that arise from this methodology for the case study are presented. The main conclusion of this paper is that the proposed methodology is quite effective in its thorough analysis and treatment of the field rework issue, and it can be used as a first step towards an industry Best Practice for measuring and classifying construction field rework. It can now be used on subsequent projects over time to collect a sufficient dataset, from which the construction industry can develop industry standards and statistics on construction field rework. [ABSTRACT FROM AUTHOR]

Managing predators to restore threatened or endangered species is often controversial. Hervieux et al. (2014; Can. J. Zool. 92(12): 1029-1037) report on the efficacy of wolf ( Canis lupus L., 1758) reduction as a recovery strategy in the Little Smoky population of boreal woodland caribou ( Rangifer tarandus caribou (Gmelin, 1788)) range in Alberta, which generated a lot of media attention. As such, the authors were invited by the journal editor who handled the original paper to write this addendum to provide clarification regarding the methodology used in the original paper. Wolf reduction was conducted by Government personnel in accordance with appropriate policy and laws (i.e., federal and provincial Species at Risk Acts; Alberta Wildlife Act; Alberta Woodland Caribou Policy). University-based researchers were involved only in data analysis and writing, and thus did not require approval by a university-based animal welfare board. Collaboration between independent university-based scientists and government biologists is essential to effective assessment of such controversial management practices. Hervieux et al. (2014; Can. J. Zool. 92(12): 1029-1037) in fact concluded that such wolf reductions, by themselves, would only 'buy time' and would not restore woodland caribou alone without effective habitat protection. [ABSTRACT FROM AUTHOR]

The oil sands in northern Alberta have been mined to produce bitumen over the past five decades. Since the 1980s, technical advances have been made in mining, material handling, and bitumen extraction. However, acquiring practical methods to control and reduce the fluid fine tailings build-up has been an ongoing challenge. Recent regulatory changes have driven the industry to review current tailings-management techniques and investigate numerous alternative technologies and processes to manage and reclaim fine tailings. Many of these fine tailings-management techniques involve some form of polymer or chemical addition to promote dewatering and strength gain to meet the regulatory requirements. Based on the reported data, the chemically amended fine tailings deposits have the characteristics of sensitive, metastable deposits, necessitating additional mitigative measures by oil sands operators beyond the regulatory requirements. This paper explores the geotechnical aspects of meeting regulatory strength performance criteria by employing flocculation-based dewatering of fluid fine tailings. [ABSTRACT FROM AUTHOR]

Interface management (IM) is one of the major keys for construction project success. The severity of interface problems for different projects does not only delay the project, but also impacts overall project performance. This paper is an extension of a previous work that defined major IM problems in Alberta's construction projects. This research study intended to investigate, identify, and classify interface problem factors in Alberta's construction projects. The study included four stages. The first stage was a comprehensive literature review, pilot studies and face-to-face interviews in industry. In the second phase, a web-page questionnaire was conducted with participants from industry. Based on that, in the last two phases, a factor analysis and Pearson's correlation matrix were applied on the collected data. The study identified six IM factors, namely: 'management', 'information, bidding and contracting', 'by-law and regulation', 'technical engineering and site issues', and 'other interface problems'. Finally, correlation between IM factors and different construction data was tested. The data analysis results provided a comprehensive view of the main causes behind IM conflicts in Alberta's construction industry. [ABSTRACT FROM AUTHOR]

This paper evaluates the dynamic flexural response of sandstone from the Paskapoo formation in Alberta. Sandstone prisms were subjected to quasi-static flexure as per ASTM while a drop-weight impact tester was employed to generate stress rates up to 108 kPa/s. Companion testing under quasi-static compression on sandstone cylinders helped establish baseline properties including the compressive strength, elastic modulus, and Poisson's ratio. It was found that the flexural strength and fracture toughness of Paskapoo sandstone obey stress rate sensitive models developed originally for concrete. However, the fracture toughness was more stress rate sensitive than its flexural strength. [ABSTRACT FROM AUTHOR]

Significant cost overruns and schedule delays on oil and gas projects in Alberta have been of great concern for many companies. The industry has indicated a need for public data to verify anecdotal conclusions that labor productivity is the root cause behind project performance problems. In this paper, a sample of 37 Alberta oil and gas projects was analyzed. The findings provided evidence that poor planning and inadequate project scope definition gave rise to project cost and schedule performance problems, while labor productivity is merely a proximate cause. High correlations are revealed between deficient project performance and factors such as low percent engineering completed before construction start, low estimation accuracy of field productivity rates, unit costs, crew sizes, and indirect costs. The results also emphasized a need to increase the level of implementation of best management practices to ameliorate the effects of the challenging project environments. [ABSTRACT FROM AUTHOR]

Advanced traveller information systems (ATIS) play a very vital role in improving traffic conditions on the roads, by providing information for drivers to assist them in making more informed travel decisions. Drivers' perceptions towards ATIS mostly define these responses. This paper examines how the use of and familiarity with different sources and media of real time traffic information updates may affect drivers' perceptions, thereby determining their responses to ATIS technology. The study employs a hybrid discrete choice model that considers interactions between latent perception and the sources of traffic information sought. Data used in this study was collected through a survey conducted among a sample of 500 commuters who use Highway 2 (Deerfoot Trail) in Calgary, Alberta, Canada. In the case of major delays due to accidents or construction on Highway 2, the City of Calgary is using 12 variable message signs (VMS) to divert drivers to alternative parallel arterials. The developed integrated discrete choice and conditional latent variable model clearly identifies an important link between the propensity to comply with VMS information and the use of other traffic information sources. One of the primary findings of this study is the existence of a significant correlation between radio traffic information, TV traffic information, and VMS displays. It was found that drivers who listen to radio traffic information or watch TV traffic channels are more likely to be compliant with VMS messages, in terms of route diversions and changes in trip destinations. [ABSTRACT FROM AUTHOR]

Vertical and horizontal patterns of light within gaps and expansion of trees into gaps were examined in young stands dominated by trembling aspen (Populus tremuloides Michx.) in northeastern British Columbia and northwestern Alberta. Lateral growth of branches of aspen edge trees averaged 15.2 cm/year and was similar to crown expansion rates reported for edge trees in eastern North America. Branches growing into gaps were significantly longer than those growing away from gaps and are likely to lead to gap shrinkage and reductions in light within gaps. However, height growth of edge trees was not significantly different from that of trees within the surrounding stands. Models describing relationships between diffuse transmittance and locations within gaps and surrounding stand height were developed in this paper. Sky view angle (SVA) was found to be effective for predicting transmittance to different locations within gaps. When SVA values exceed 1.2 (at the B.C. sites), white spruce (Picea glauca (Moench) Voss) will receive <40% of full sunlight, which is less than optimal for spruce height growth. [ABSTRACT FROM AUTHOR]

This paper reports on a laboratory investigation into the performance of a novel stacked drop manhole design where two identical rectangular manholes are stacked one beside the other but at different heights so that there is a drop in elevation from one to the other. The focus of the study was to estimate the energy dissipation that occurs in such stacked manholes during diverse inflow conditions. Flow regimes inside the structure were identified and the effectiveness of the design was assessed under variable inflow conditions. Total energy dissipation in the stacked manhole was found to range from about 50% to 90%, and the contribution of each manhole chamber to the overall energy dissipation was assessed. A relationship between water depths in the manhole chambers and the corresponding outflow conditions was established. In addition, an analysis of the flow patterns and flow regimes highlighted the relevant parameters involved in the mechanisms of energy dissipation. [ABSTRACT FROM AUTHOR]

This paper presents the results of structural mapping in the Peace River Arch region, obtained by applying a refined trend surface analysis to existing well-log data. Maps generated with the new approach allow for accurate location of formation-top offsets and recognition of faults associated with small, metre-scale offsets. Consequently, new faults were identified in the Mesozoic strata, and faults previously recognized as only offsetting Paleozoic strata were found to extend into the Cretaceous strata but with much smaller formation-top offsets. This provided direct evidence for re-activation of the Dawson Creek Graben Complex (DCGC) during the Cretaceous. An additional structural feature named Clear River Graben was recognized to have affected Permian to Jurassic strata. Relationships among previously interpreted faults were clarified and the structural controls on the DCGC were more accurately evaluated. [ABSTRACT FROM AUTHOR]

A skeleton of a new ceratopsid dinosaur, Eotriceratops xerinsularis gen. et sp. nov., is described in this paper. It is the first associated vertebrate skeleton found within the upper 20 m of the Horseshoe Canyon Formation. Eotriceratops xerinsularis is a large chasmosaurine that differs from other chasmosaurines in a unique set of features in the premaxilla, nasal horn core, squamosal frill, and epijugal. The most striking of those features includes an extremely tall, non-recessed narial process of the premaxilla; the presence of greatly elongate, spindle-shaped epoccipitals on the squamosal frill; a deep, well-demarcated fossa on the anteroventral surface of the squamosal frill; a sharply conical epijugal with a pronounced proximoposterior process and separate fossa-like facets for the jugal and quadratojugal; and the presence of an obliquely extending vascular trace meeting a transverse vascular trace ventrally on the anterior surface of the nasal horn core. Our phylogenetic analysis suggests that E. xerinsularis is nested within a clade including Triceratops, Diceratops, and Torosaurus, which are all from late Maastrichtian deposits. The upper 20 m of the Horseshoe Canyon Formation comprises a coal-rich interval (Carbon–Thompson coal zone, unit 5), which previously has been assigned to upper Maastrichtian magnetochrons 31n and 30r, and the Mancicorpus gibbus miospore subzone. The ceratopsid specimen was collected from between the Carbon and Thompson coal seams, and thus, is inferred to (1) occur near the top of magnetochron 31n and (2) have an age of 67.6–68.0 Ma. Large chasmosaurine ceratopsids, such as Triceratops and Torosaurus, have not previously been described from the Horseshoe Canyon Formation or from magnetochron 31n or the M. gibbus miospore subzone. Thus, Eotriceratops is distinctly older than any other ceratopsid in the Triceratops group, and the discovery of E. xerinsularis helps fill a biostratigraphic gap between early and late Maastrichtian chasmosaurines. [ABSTRACT FROM AUTHOR]

Full-scale laboratory tests were carried out at the University of Alberta to investigate the post-wrinkling ultimate behavior of steel pipelines. The pipe specimens exhibited extreme ductile behavior and did not fail in fracture under monotonically increasing axisymmetric compressive axial loads and displacements. Fractures developed at the wrinkled region, however, when a wrinkled pipe specimen was subjected to cyclic strain reversals due to unloading and loading of primary loads. This paper presents test procedures, complete post-wrinkling behavior, fracture limit strain values, and fracture configurations obtained from full-scale tests on wrinkled pipe specimens under cyclic and monotonic axial loadings. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of all documented ice jam release events for the Athabasca River at Fort McMurray, Alberta. A review of the historical records indicates that release waves in excess of 3 m and propagation speeds of 4–5 m/s are not uncommon. Numerous occurrences of increases in wave speed and magnitude suggest that temporary stalling of ice runs may be a significant factor in release event propagation. Detailed measurements of ice jam release events in 2001–2003, including most notably a 4.3 m high release wave measured in 2002, provide unprecedented data describing ice jam release wave propagation and suggest that continued propagation of a portion of the release wave downstream of a reformed jam could be a significant factor in immediate re-release. [ABSTRACT FROM AUTHOR]

Spring breakup on northern rivers can result in ice jams that present severe flood risk to adjacent communities. Such events can occur extremely rapidly, leaving little or no advanced warning to residents. Fort McMurray, Alberta, is one such community, and at present no forecasting model exists for this site. Many of the previous studies regarding ice jam flood forecasting methods, in general, cite the lack of a comprehensive database as an obstacle to statistical modelling. This paper documents the development of an extensive database containing 106 variables, and covering the period from 1972 to 2004, that was created for ice jam forecasting on the Athabasca River. Through multiple linear regression analysis, equations were developed to model the maximum water level during spring breakup. The optimal model contained a combination of hydrological and meteorological data collected from early fall until the day before river ice breakup. The number of historical years of data, rather than the scope of variables, was found to be the major limitation in verifying the results presented in this study. [ABSTRACT FROM AUTHOR]

For decades, many researchers have reported the decline in construction productivity, but it is impossible to generalize the productivity problems due to issues such as geographical differences, weather changes, skill level differences in the labour force, and workload demand. There are currently approximately 160 000 construction workers in Alberta, and the value of ongoing and future projects in the oil and gas sector alone is over Can$200 billion. Because of the high demand and necessity for a comprehensive research study for Alberta to improve construction productivity, a 2 year study commenced with the collaboration of four eminent contractors to investigate human, management, and external issues. Under human issues, 101 construction workers in the carpentry trade were observed, interviewed, and surveyed by questionnaire. This paper discusses the research method, results, and recommendations of the productivity research specific to the human issues. These recommendations were communicated to the contractors for improving the human issues by developing and analyzing a new expectancy model considering construction workers' effort and performance and the tool times observed to mitigate the reasons for non-tool time. [ABSTRACT FROM AUTHOR]

Recent archaeological excavations at a deeply stratified site in northwest Calgary, Alberta have uncovered four occupation layers spanning the interval from 8000 to 2000 BP. Depending on the dating one accepts for the Holocene thermal maximum, two or more of these occupations occurred during this interval of aridity. This site thus provides a record of human occupation during the Archaic (Middle Prehistoric I) period in the Calgary area. More importantly, the site occurs in an upland setting, apparently far removed from reliable sources of water and normal environments of deposition. Yet, the cultural deposits occur in sediments which extend 2 m below surface and include five sedimentary units as well as a minimum of three pedogenic units. This paper presents the results of geoarchaeological research on the changing landscape for the site and notes the implications of these changes for the study of Archaic manifestations on the northern Plains. [ABSTRACT FROM AUTHOR]

Linear developments such as roads, seismic lines, and pipeline rights-of-way are common anthropogenic features in the boreal forest of Alberta. These features may act as barriers to the movement of threatened woodland caribou, Rangifer tarandus caribou. Seismic lines were not barriers to caribou movements, whereas roads with moderate vehicle traffic acted as semipermeable barriers to caribou movements. Twenty-two adult female and 1 adult male woodland caribou were captured and collared on February 17–19, 1998. Each caribou was fitted with a global positioning system collar. The greatest barrier effects were evident during late winter, when caribou crossed actual roads 6 times less frequently than simulated road networks. Semipermeable barrier effects may exacerbate functional habitat loss demonstrated through avoidance behavior. Caribou may cross roads less frequently than expected for a number of reasons, including an aversion to the physical barrier presented by a road and associated forest opening, vehicle traffic, or predation by humans. The effects of habitat fragmentation through habitat loss, avoidance, and the semipermeable barrier effects of roads should be considered in developing strategies to maintain woodland caribou populations in Alberta. Roads that act as semipermeable barriers to caribou movements may make the presence of caribou more predictable in space and time, and hence compromise the "spacing out" strategy that caribou adopt to reduce predation. The approach we have outlined in this paper is a useful method to quantify the effects of human developments acting as semipermeable barriers to animal movements and should be considered in the development of animal-movement models.

This paper reviews the factors and criteria for the design of new and the retrofitting of existing dry detention ponds to enhance removal of total suspended solids (TSS) from stormwater. Detention time is discussed as the most important factor affecting TSS removal. Two-stage facilities and multi-level outlet design are important means of enhancing TSS removal in dry ponds. Two dry ponds within the city of Edmonton were selected to evaluate their TSS removal. The level of expected TSS removal is low owing to the relatively short detention times for both ponds. Methods for retrofitting the dry ponds to enhance TSS removal are discussed.Key words: dry pond, stormwater, TSS removal, detention time, retrofitting.Cet article passe en revue les facteurs et critères de conception de nouveaux étangs de rétention, et de modification de ceux déjà existants, avec pour but d'améliorer la capacité d'enlèvement des substances solides totales en suspension (SST) contenues dans les eaux de ruissellement. Le temps de rétention est examiné en tant que facteur principal affectant l'enlèvement des SST. Les installations à deux étages et la conception de sorties multi-niveaux sont des procédés importants qui améliorent l'enlèvement des SST dans les étangs. Deux étangs de la Ville d'Edmonton ont été sélectionnés et leur capacité de rétention a été évaluée. Le niveau d'enlèvement des SST escompté est bas compte-tenu des temps de rétention relativement courts de ces deux étangs. Les méthodes de modification des étangs visant à améliorer l'enlèvement des SST sont examinées.Mots clés : étang, eaux de ruissellement, enlèvement des SST, temps de rétention, réajustement.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This special issue reports on some of the results of a multi-disciplinary research program conducted in the Boreal Plains of northwest Alberta and northeast British Columbia. Several innovative approaches to conducting geoscientific research in this remote drift-covered region are presented, including geochemical analysis of bentonites for evaluating kimberlite potential, the use of electromagnetic surveys for mapping buried aggregate deposits, and paleo-topographic mapping techniques to define buried channels. Results of the program include the discovery of several large aggregate deposits, the first kimberlite indicator minerals in northeast British Columbia, a significant sphalerite dispersal train in northwest Alberta, the first documented report of kimberlite-sourced bentonites, and numerous previously unknown interglacial sites. Together these papers provide a greatly enhanced understanding of the glacial history, Quaternary stratigraphy, and kimberlite geology of northwest Alberta and northeast British Columbia and provide an improved framework for resource exploration in the region. Ce numéro spécial fait le point sur quelques résultats d’un programme de recherche multidisciplinaire effectué dans les plaines boréales du nord-ouest de l’Alberta et du nord-est de la Colombie-Britannique. Plusieurs approches innovatrices de recherche géoscientifique dans cette région éloignée recouverte de sédiments glaciaires sont présentées, incluant l’analyse géochimique des bentonites pour l’évaluation du potentiel kimberlitique, l’utilisation de relevés électromagnétiques pour cartographier des dépôts enfouis d’agrégats et des techniques de cartographie paléotopographique dans le but de définir des chenaux enfouis. Les résultats du programme comprennent la découverte de plusieurs grands dépôts d’agrégats, des premiers minéraux indicateurs de kimberlite dans le nord-est de la Colombie-Britannique, une traînée importante de dispersion glaciaire de sphalérite dans le nord-ouest de l’Alberta, la première documentation de bentonites dont la source est une kimberlite et de nombreux sites interglaciaires inconnus à ce jour. Ensemble, ces articles fournissent une bien meilleure compréhension de l’historique glaciaire, de la stratigraphie du Quaternaire et de la géologie des kimberlites dans le nord-ouest de l’Alberta et le nord-est de la Colombie-Britannique; ils fournissent aussi un meilleur encadrement d’exploration pour les ressources dans cette région. [ABSTRACT FROM AUTHOR]

Field and laboratory measurements of the transport of the suspended sediment from the Athabasca River near Hinton, Alberta, Canada are described. The objective of these measurements was to examine the influence of pulp mill effluent entering the river from a nearby pulp mill on suspended sediment. The results of the field measurement showed that the effluent had significant impact on the transport of the sediment. Specifically, the effluent increased the deposition rates of the sediment and caused a substantial reduction of sediment concentrations in reaches downstream of the effluent outfall. The reduction in sediment concentrations and the concomitant sediment loads can only be attributed to the pulp mill effluent as there were no abrupt changes in the hydraulic characteristics of the river in the reach of interest. These observations were confirmed by laboratory experiments that were carried out using a rotating circular flume located at the National Water Research Institute in Burlington, Ontario, Canada. The findings of this study have implications for modelling suspended sediment transport in rivers receiving bleached pulp mill effluents. [ABSTRACT FROM AUTHOR]

In the past few years, artificial neural networks (ANNs) have been used in describing and modelling wastewater treatment processes. Artificial neural network models can be identified without a detailed knowledge of the kinetics of the system to be modelled. Also, ANN models can potentially contain a great deal of information about the system itself, including the same type of information contained in conventional deterministic models. The fact that these models can be continuously updated with minimal resource requirements makes them very attractive for application in a real-time control scenario. In the current paper, applications of ANNs in the field of wastewater treatment performance prediction are reviewed. In addition, this paper presents a case study that reports some comprehensive modelling work to develop nonlinear neural network prediction models for the Gold Bar Wastewater Treatment Plant (GBWWTP), the largest sewage treatment facility in Edmonton, Alberta. [ABSTRACT FROM AUTHOR]

This paper examines the application of the artificial neural network (ANN) modeling technique to model a lime softening process at a full-scale drinking water treatment facility. The modeling was done for the Rossdale Water Treatment Plant (WTP) operated by EPCOR Water Services Inc. in Edmonton, Alberta. It was determined that ANN can model a lime clarifier accurately and with superior performance to other modeling methods. During the development stage, a prediction of alum clarifier pH also becomes necessary, and a very accurate inferential (virtual) sensor for pH was developed using ANN. The ANN models were also integrated with the Supervisory Control and Data Acquisition (SCADA) system of the plant so that real-time predictions of lime doses and effluent total hardness could be monitored. It was shown that the performance of the ANN models that were developed using average daily values for the parameters also work well when they are executed in real time. [ABSTRACT FROM AUTHOR]

Artificial neural network (ANN) technology has evolved from the experimental stage into actual industrial applications. To achieve this significant transition, careful planning and adjustment are required. This paper illustrates such an example in the water treatment industry. The project objective is to upgrade the ANN models from a previous research project and install the system on-line in the Rossdale Water Treatment Plant in Edmonton, Alberta, Canada, to forecast raw water colour one day ahead. The article discusses the important issues and techniques to upgrade the neural network model to the actual application. Furthermore, sufficient communication is also required between the designers and the users to address the applicability and user friendly issues in model implementation. Failure in communication can render the whole process ineffective. Possible improvements are also recommended for the future on-line applications. [ABSTRACT FROM AUTHOR]

This paper reports on the application of artificial neural network (ANN) techniques for predicting the concentration of trihalomethanes (THMs) in finished water at the E.L. Smith Water Treatment Plant (WTP) in Edmonton, Alberta, Canada. The formation of THMs in finished water involves many complex chemical reactions and interactions that are difficult to model using conventional methods. The formation of THMs has been found to be correlated to raw and treated water quality characteristics such as colour, pH, and temperature and chemical addition such as chlorine, alum, and powder activated carbon (PAC). Three models were derived using raw water, post clarification water, and a combination of raw and post clarification water parameter inputs. The model that most successfully predicted the concentration of THMs in finished water is the model that uses clarifier effluent parameter inputs. This model can be used at the E.L. Smith WTP for early detection of potentially high THM concentrations in finished water and gives plant operators enough advanced warning to reduce THM precursors. With an adequate understanding of water treatment plant processes and THM formation potential it will be fairly easy for any water treatment facility, which has a few years of historical plant data, to develop its own ANN model for predicting the formation of THM in finished water. [ABSTRACT FROM AUTHOR]