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The process of icing involves the freezing of overflow layers, on ground or within streams, and results in ice bodies called "aufeis" that are common in most northern landscapes. Knowledge about aufeis is still limited despite the cold region engineering challenge they represent. Understanding the causes of overflow events leading to aufeis development represents a key for the prediction, mitigation, and management of this geohazard and can also support the planning and design of infrastructure in the North. This paper introduces a practical classification for the diverse range of overflow processes that generate aufeis, including under-represented processes, such as the instability of winter streamflow. Importantly, it distinguishes flow conveyance from water supply overflow processes and describes the temporal aspect of icing intensity. Finally, research topics are proposed to improve our understanding of aufeis, including their predictability, the impact of climate change on their occurrence and extent, and stream morphology–aufeis interaction. [ABSTRACT FROM AUTHOR]

The recent expansion of municipality limits has resulted in an increase in the wildland–urban interface, causing fires in the wildlands to potentially encroach and enter urban centers. This paper proposes a fire-risk modeling framework within a climate resiliency context. The study uses large-scale geospatial datasets in combination with the analytical hierarchy process. Using various high-resolution-detailed datasets, an extensive list of variables was utilized to develop a novel fire-risk model. To support the goal of creating a climate-resilient urban municipality, an ecological vulnerability classification map was constructed to identify developable areas and areas under preservation. Regarding creating awareness for climate adaptation and zone, a brief discussion on the role of each stakeholder is provided. The discussion covers strategies for fire prevention and mitigation in high-risk areas/zones, as well as establishing several cornerstones for strategic planning and action to strengthen climate resilience of urban communities. [ABSTRACT FROM AUTHOR]

Canada's climate is warming at a rate about double the global average, leading to potential negative impacts on public infrastructures such as jointed plain concrete pavement (JPCP). In light of this reality of changing climate, the work contained in this paper is aimed at evaluating JPCP's early-age behaviour in response to environmental conditions. HIPERPAV® software and the associated models developed by the U.S. Federal Highway Administration (FHWA) were used to identify cracking potential. A sensitivity analysis was performed to assess the effect of different levels of air temperature, mix temperature, base layer temperature, wind speed, and relative humidity. Additionally, projected extreme temperatures predicted by the Canadian Regional Climate Model (CanRCM) were used to determine the relative impact of climate change on cracking risk. The results demonstrated the increased cracking risk under changing climate in several Canadian cities by mid-century and highlighted the importance of developing a pathway forward for climate adaptation. [ABSTRACT FROM AUTHOR]

Research often ranges from incremental innovations of existing approaches to the development of novel methodologies. The current study seeks to combine both paradigms through consideration of a legacy hydro system. Stretched along the border between Canada and the US and regulated by a 1950 treaty, the Niagara River currently provides almost 5000 MW of renewable power. This paper develops a HEC-ResSim representation of the existing reservoir (power) system and uses this model to explore a variety of possible future scenarios. These possibilities will ultimately include considering the sensitivity of the system to climate change, reducing tourist flows, and exploring using additional storage to augment operational flows, although the current paper particularly details the scenario involving increased power diversion by somewhat relaxing treaty restrictions. Such an arrangement is shown to potentially increase monthly hydro discharges by 16% relative to the current baseline, and thus to permit an additional 1050 GWh of annual generation on the Canadian side alone. This preliminary exploratory study simply evaluates the potential hydro benefits by assessing the interplay between various system constraints if treaty provisions were ever to be reconsidered, and thus sets the stage for considering a variety of other scenarios. [ABSTRACT FROM AUTHOR]

Major ice jam floods occurred along the Saint John River at Perth-Andover, New Brunswick, in 1976,1987,1993, 2009, and 2012. These floods have been devastating and resulted in relocation or demolition of many buildings in affected areas of the community. The purpose of this paper is to review ice processes along the Saint John River from Grand Falls to Beechwood Dam and their relevance to the ice-related problems that have occurred in Perth-Andover. The HEC-RAS program was chosen for ice jam flood stage computations, and cross-sectional, roughness and flow information entered to create a model of the study reach. The model was calibrated using field data obtained on 31 March 2000 along an ice jam in the Perth-Andover area. Model applications resulted in stage-discharge relationships for ice jams of different lengths and locations within the study stretch (Beechwood Dam to Grand Falls). These relationships indicate that ice jams can cause flooding at Perth-Andover, even with moderate spring breakup flows. The variation of ice jamming potential along the study stretch, and its relation to reservoir bathymetry and slope, are discussed. The increase in the number and severity of ice jam floods that have affected Perth-Andover may have resulted from changes in infrastructure and climate that have occurred since the 1950s. Local ice problems are likely to be aggravated over the next few decades but tempered in the longer term if the climate continues to change according to current projections. [ABSTRACT FROM AUTHOR]

The ice conditions in a regulated river will depend on the climatic changes as well as the changes to the hydropower operation strategies in the future. The existing literature shows that very few studies have been carried out to investigate the impact of climate change on the river ice regime, which is important for operation of hydropower in cold climates. In this study, a series of modelling tools have been used to transform the climate change signal in terms of precipitation and air temperature into cross-section based river ice assessment in a basin with a complicated hydropower system. The study is based on the EURO-CORDEX climate change data extracted from a regional climate model driven by a suite of five general circulation models with three representative concentration pathways. Hydrological model simulation results show that the winter and spring flow will be increased, which will have an impact on the river ice conditions towards the middle and end of this century. Reservoirhydropower model simulation shows that the production flows in the winter will be increased in the future. River ice model simulation shows the number of days with freezing water temperature are reduced in the future climate, and correspondingly days with frazil ice are reduced at most of the locations in the study area. The future period with ice cover will also be shortened. The paper also demonstrates a general methodology and procedure to simulate future ice conditions in a regulated river combining multiple models and data sets. [ABSTRACT FROM AUTHOR]

The Canadian Society for Civil Engineering in its Vision 2020 statement identified sustainability in infrastructure as a core element for the civil engineering profession. However, what is sustainable infrastructure and more importantly, how can it be assessed? This paper uses stormwater infrastructure as its primary example to explore these issues, reviews issues with stormwater infrastructure in Canada, and critically examines current sustainability assessment methods. Two groups of problems are identified. The first group concerns issues related to economic, institutions, population growth, ecological, and health and safety. The second group examines the uncertainties in impact prediction associated with climate change effects as well as health impacts on the user. Sustainability evaluation methods (ranking, sustainability indicators, footprint, metabolism, extended metabolism, life cycle assessment), performance assessment tools, infrastructure report card, and the public infrastructure engineering vulnerability committee protocol for climate change assessment are then reviewed. Current methods of assessing infrastructure mostly focus on the functional aspects of the system with resource use reduction as the primary objective. However, they do not explicitly concentrate on resiliency and long-term sustainability, nor do they consider the associated health implications and change management capabilities for long-term sustainability. A new comprehensive framework would be required to assess broad, emerging issues related to infrastructure. [ABSTRACT FROM AUTHOR]

Given anticipated climate change and its inherent uncertainty, a pavement could be subjected to different climatic conditions over its life and might be inadequate to withstand future environmental stresses beyond those currently considered during pavement design. This paper incorporates climate change effects into the mechanistic-empirical (M-E) based pavement design to explore potential climate change and its uncertainty on pavement design and performance. Three important questions are addressed: (1) How does pavement performance deteriorate differently with climate change and its uncertainty? (2) What is the risk if climate change and its uncertainty are not considered in design? and (3) How do pavement designers respond and incorporate this change into M-E design ? Three test sites in the United States are examined and results demonstrate a robust and effective approach to integrate climate change into pavement design as an adaptation strategy. [ABSTRACT FROM AUTHOR]

This paper evaluates the National Centers for Environmental Prediction - National Center for Atmospheric Research (NCEP-NCAR) reanalyses hydroclimatic data as an initial check for assessment of hydrologic impacts of climate change at the basin scale. A reanalysis dataset for daily precipitation, maximum temperature, and minimum temperature from the NCEP-NCAR global (NNGR) and regional (North American Regional Reanalysis or NARR) reanalysis project has been used as input into the semidistributed hydrologic model (Hydrologic Engineering Center Hydraulic Modeling System or HEC-HMS) for the period 1980-2005. An extensive analysis has been performed for assessing the performance of the reanalysis data generated flows compared with the observed inputs during May-November. The stream flows generated from the NARR dataset show encouraging results in simulating summertime low flows with less variability and fewer errors. The results indicate that NNGR results are less accurate and highly variable. This study suggests that NARR can be adequately used as an alternative in data-scarce regions. Le présent article évalue les nouvelles analyses des « NCEP-NCAR (« National Centers for Environmental Prediction-National Center for Atmospheric Research) » de données hydroclimatiques pour une vérification initiale de l’évaluation des impacts hydrologiques des changements climatiques à l’échelle du bassin. L’ensemble de données pour la nouvelle analyse des précipitations quotidiennes, de la température maximale et de la température minimale du projet de nouvelle analyse « NCEP-NCAR » (a) global (« NNGR ») et (b) régional (« NARR ») a été utilisé comme intrant dans le modèle hydrologique semi-réparti (« HEC-HMS ») pour la période 1980-2005. Une analyse approfondie a été réalisée afin d’évaluer le rendement des données des débits générés par la nouvelle analyse par rapport aux intrants observés entre mai et novembre. Les débits d’eau générés à partir de l’ensemble de données NARR montrent un résultat encourageant pour la simulation des faibles débits d’étiage comportant moins de variabilité et d’erreurs. Les résultats ont indiqué que les résultats NNGR sont moins précis et très variables. La présente étude suggère que NARR peut être utilisé adéquatement comme solution de remplacement dans les régions pour lesquelles les données sont peu abondantes. [ABSTRACT FROM AUTHOR]

Winter can be a critical time on many rivers, during which ice conditions and a number of environmental factors can lead to rapidly developing and damaging flood events. Also, in northern Canada, rivers are important for both summer (ferry) and winter (ice bridge) transportation; however, during periods of variable ice conditions these transportation links are temporarily interrupted. As a result, northern communities can become isolated for periods of time. With climate warming becoming an increasing concern, it is important to know how elevated temperatures might affect river ice covers so that we can assess the implications for ice jam events, hydropower dam operation, and winter transportation. The Peace River in northern British Columbia and Alberta was used as a case study in this paper to assess the validity of a newly developed, public domain, thermo-hydraulic river ice model, River1D. The Canadian second-generation coupled global climate model (CGCM2) provided an offset for the historical air temperature input, and a future climate analogue for the mid-21st century ice regime was generated. The historical and future climate simulation results indicated significant potential reductions in the duration and extent of ice cover on the Peace River and a longer period over which the river will be impassible by ferry or ice bridge. Specifically, the number of days an ice bridge could be sustained at the Shaftesbury Ferry site was shown to decrease by 60% to 78%. [ABSTRACT FROM AUTHOR]

The passage of river ice during the breakup event can have several effects on bridge structures. Design for ice passage at bridges has largely been empirical, such as the determination of superstructure clearance requirements based on historical stage data. As hydrologic and river ice processes in rivers are modified by climatic change, the use of empirical methods based on past observations and measurements could become less reliable. To advance beyond empiricism, it is necessary to develop rational design criteria based on a thorough understanding of the factors governing the interaction between bridges and ice. This concern applies especially during the breakup event when river flows, velocities, and hydrodynamic forces are usually higher and moving ice is thicker and stronger than during freeze-up. This paper provides guidance on the design of bridges to minimize ice impacts on the structure during the breakup period. [ABSTRACT FROM AUTHOR]