Alaska Highway Research Articles

Dead mammal walking: A month‐long march by a bison (Bison bison) after an ungulate–vehicle collision

AbstractGlobally, ungulate–vehicle collisions (UVCs) are a major human safety concern and may also represent a significant source of mortality for some ungulate populations. However, records of UVC based on counts of roadside carcasses or reports by drivers involved in these incidents are assuredly underestimated because not all ungulates struck die immediately or at the roadside or are reported by drivers or authorities. Here, we provide an observation and analysis of the movements of a GPS‐collared bison (Bison bison) that was involved in a UVC on the Alaska Highway and died in a thick boreal forest 29 days later. During that time, she moved 49.7 km from where she was hit. Her daily movement rate (in kilometers per hour) and daily net displacement (in kilometers per day) were significantly greater in the 29‐day period before she was struck compared with 29 days afterward. This vivid example illustrates that individuals injured in a UVC can die several weeks later and at a considerable distance from where they were initially struck. Moreover, when they eventually die, it may be where their carcass would not be found or associated with a UVC. Bison are the largest land mammal in North America and perhaps more robust to some lower impact UVC than smaller bodied species. Even so, if not for the GPS collar on this bison, we would have never known the fate of this individual, and the carcass likely never found. Taken together, the movements and final resting place of this bison illuminate how estimates of mortality as a result of UVC can be underestimated when the animal does not die immediately and in a location where it can be found. Given our data, we further urge managers to consider roadside counts of animals killed in UVC as a minimum estimate when considering options for mitigation.

Qualitative evaluation of thaw settlement potential in permafrost regions of Canada

Permafrost thaw negatively impacts the built environment in circumpolar regions. Thaw-induced settlement causes various engineering problems such as differential settlement, sinkholes, culvert failures, and pipeline deformations. Large-scale pre-construction evaluation reduces the risk of building infrastructure in thaw settlement-prone areas. This evaluation enables the comparison and screening of multiple route/location alternatives, the identification of vulnerable sections of a route, and the development of more effective site investigation plans. This study presents a systematic approach for evaluating thaw settlement potential in various regions across Canadian permafrost. In developing the approach, we considered three main factors: ground ice content, surficial deposit unit, and bedrock type. These factors were prioritized based on their relative importance in defining settlement behaviour, and a weighting factor was determined for each. In this study, the weighting factors of 0.78, 0.15, and 0.07 were suggested for ground ice content, surficial deposit type and bedrock type, respectively. We subsequently developed a Thaw Settlement Potential Index (TSPI), which can be calculated for any given location using publicly available Canada-wide resources. We calculated TSPI for several reported cases of thaw settlement issues across Canada and compared the results with site observations. A comparison was also made with a more detailed assessment conducted on the Northern Alaska Highway using a different approach. While the TSPI assessment required minimal time, effort, and resources, the obtained results generally matched those of finer-scale assessments with more detailed information. Thus, our methodology simplifies early identification of thaw-unstable regions in projects with large footprints and helps allocate resources more efficiently for subsequent site investigations.

Subsurface Porewater Flow Accelerates Talik Development Under the Alaska Highway, Yukon: A Prelude to Road Collapse and Final Permafrost Thaw?

AbstractThe presence of taliks (perennially unfrozen zones in permafrost areas) adversely affects the thermal stability of infrastructure in cold regions, including roads. The role of heat advection on talik development and feedback on permafrost degradation has not been quantified methodically in this context. We incorporate a surface energy balance model into a coupled groundwater flow and energy transport numerical model (SUTRA‐ice). The model, calibrated with long‐term observations (1997–2018 on the Alaska Highway), is used to investigate and quantify the role of heat advection on talik initiation and development under a road embankment. Over the 25‐year simulation period, the new model is driven by reconstructed meteorological data and has a good agreement with near surface soil temperatures. The model successfully reproduces the increasing depth to the permafrost table (mean absolute error <0.2 m), and talik development. The results demonstrate that heat advection provides an additional energy source that expedites the rate of permafrost thaw and roughly doubles the rate of permafrost table deepening, compared to purely conductive thawing. Talik initially formed and grew over time under the combined effect of water flow, snow insulation, road construction and climate warming. Talik formation creates a new thermal state under the road embankment, resulting in acceleration of underlying permafrost degradation, due to the positive feedback of heat accumulation created by trapped unfrozen water. In a changing climate, mobile water flow will play a more important role in permafrost thaw and talik development under road embankments, and is likely to significantly increase maintenance costs and reduce the long‐term stability of the infrastructure.

Air-convection-reflective sheds: A mitigation technique that stopped degradation and promoted permafrost recovery under the Alaska Highway, south-western Yukon, Canada

This study tested the efficacy of air-convection-reflective sheds (ACRS) installed along the Alaska Highway in Yukon (Canada) as a mitigation technique to reduce heat absorption during the thawing season and to increase heat loss during the freezing season. Soil surface, air, and ground temperatures were recorded under the ACRS between 2008 and 2016, which were then compared with values from an unmitigated road embankment and from the natural ground near the road embankment. The design of the ACRS blocked incoming solar radiation, prevented snow accumulation, and promoted air convection through the stack effect, which resulted in a cooling efficiency of 358% compared to the reference site. The net heat loss resulted in a 6.3 °C cooling of the average soil surface temperature and caused the active layer thickness to decrease by nearly two meters, thus stopping permafrost warming and promoting permafrost recovery and its upward aggradation in the embankment. Implementations of the ACRS in specific vulnerable or degraded sections of roads and airstrips represents a viable solution to permafrost thaw and embankment failure.

Surface energy balance of sub‐Arctic roads with varying snow regimes and properties in permafrost regions

AbstractSurface energy balance (SEB) strongly influences the thermal state of permafrost, cryohydrological processes, and infrastructure stability. Road construction and snow accumulation affect the energy balance of underlying permafrost. Herein, we use an experimental road section of the Alaska Highway to develop a SEB model to quantify the surface energy components and ground surface temperature (GST) for different land cover types with varying snow regimes and properties. Simulated and measured ground temperatures are in good agreement, and our results show that the quantity of heat entering the embankment center and slope is mainly controlled by net radiation, and less by the sensible heat flux. In spring, lateral heat flux from the embankment center leads to earlier disappearance of snowpack on the embankment slope. In winter, the insulation created by the snow cover on the embankment slope reduces heat loss by a factor of three compared with the embankment center where the snow is plowed. The surface temperature offsets are 5.0°C and 7.8°C for the embankment center and slope, respectively. Furthermore, the heat flux released on the embankment slope exponentially decreases with increasing snow depth, and linearly decreases with earlier snow cover in fall and shorter snow‐covered period in spring.

Field and numerical studies on the thermal performance of air convection embankments to protect side slopes in permafrost environments

Shoulder air convection embankments (ACEs) are sufficient to counter the effect of ground staying relatively warm due to the insulation of snow accumulation on side slopes of northern transportation infrastructure. However, little information is available for the design procedure. This paper aims to propose new design guidelines and an engineering design chart to quantify the heat extraction capacity of shoulder ACEs. The tested shoulder ACE, constructed on the Alaska Highway at Beaver Creek, Yukon, in 2008, provided valuable data for the assessment of field performance and model development. Thermistor strings were installed under the centerline and under the side slope. Measurements indicated that the cooling of ground soils was significant mainly under the side slope during the monitoring years from 2009 to 2013. The data collected were also used to calibrate a coupled conduction-convection model to reproduce the thermal conditions and the changing temperature trend in the subgrade. An engineering design chart was developed based on the calibrated model, and was successfully validated using the thermal data from the Puvirnituq airstrip in Northern Quebec, Canada.

Modeling the thermal response of air convection embankment in permafrost regions

Permafrost degradation under transportation infrastructure often results in thaw settlement due to thawing of the ice-rich subgrade. Climate change is associated with permafrost-related engineering problems. Air convection embankments (ACE) have been proven to be an effective method to prevent permafrost thawing, in response to climate change. Poorly-graded aggregates are used to facilitate the air flow in an ACE, especially during winter when the air density gradient is unstable. A large-scale ACE test section was constructed along the Alaska Highway in 2008 at Beaver Creek, Yukon, Canada, to investigate the heat extraction capacity of ACEs. Boreholes under the toe, the side slope and the centerline were drilled and instrumented. Temperature data collected at this site were used to investigate the thermal performance of the ACE and to calibrate a 2D thermal model that was developed based on the Beaver Creek experimental site. Specific site characteristics, such as air temperature, foundation soil properties and embankment dimensions, were measured and used as input parameters to improve the accuracy of the 2D model developed. A relatively new approach based on heat balance at the embankment-soil interface has been proposed to investigate the heat extraction capacity of ACEs. After satisfactory calibration of the model at the Beaver Creek site, an engineering design chart has been developed and is proposed to assess the heat balance at the embankment-soil interface for different embankment thicknesses and site conditions.

Evidence for Large Holocene Earthquakes along the Denali Fault in Southwest Yukon, Canada

ABSTRACTThe Yukon–Alaska Highway corridor in southern Yukon is subject to geohazards ranging from landslides to floods and earthquakes on faults in the St. Elias Mountains and Shakwak Valley. Here we discuss the late Holocene seismic history of the Denali fault, located at the eastern front of the St. Elias Mountains and one of only a few known seismically active terrestrial faults in Canada. Holocene faulting is indicated by scarps and mounds on late Pleistocene drift and by tectonically deformed Pleistocene and Holocene sediments. Previous work on trenches excavated against the fault scarp near the Duke River reveals paleoseismic sediment disturbance dated to ∼300–1,200, 1,200–1,900, and 3,000 years ago. Re-excavation of the trenches indicates a fourth event dated to 6,000 years ago. The trenches are interpreted to show a negative flower structure produced by extension of sediments by dextral strike-slip fault movement. Nearby Crescent Lake is ponded against the fault scarp. Sediment cores reveal four abrupt sediment and diatom changes reflecting seismic shaking at ∼1,200–1,900, 1,900–5,900, 5,900–6,200, and 6,500–6,800 years ago. At the Duke River, the fault offsets sediments, including two White River tephra layers (∼1,900 and 1,200 years old). Late Pleistocene outwash gravel and overlying Holocene aeolian sediments show in cross section a positive flower structure indicative of post-glacial contraction of the sediments by dextral strike-slip movement. Based on the number of events reflecting ∼M6, we estimate the average recurrence of large earthquakes on the Yukon part of the Denali fault to be about 1,300 years in the past 6,500–6,800 years.

Connecting Physical and Racial Divides: The Alaska Highway

Connecting Physical and Racial Divides: The Alaska Highway

Impact of heat advection on the thermal regime of roads built on permafrost

AbstractIn northern regions, transportation infrastructure can experience severe structural damages due to permafrost degradation. Water infiltration and subsurface water flow under an embankment affect the energy balance of roadways and underlying permafrost. However, the quantification of the processes controlling these changes and a detailed investigation of their thermal impacts remain largely unknown due to a lack of available long‐term embankment temperature data in permafrost regions. Here, we report observations of heat advection linked to surface water infiltration and subsurface flow based on a 9‐year (from 2009 to 2017) thermal monitoring at an experimental road test site built on ice‐rich permafrost conditions in southwestern Yukon, Canada. Our results show that snowmelt water infiltration in the spring rapidly increases temperature in the upper portion of the embankment. The earlier disappearance of snow deposited at the embankment slope increases the thawing period and the temperature gradient in the embankment compared with the natural ground. Infiltrated summer rainfall water lowered the near‐surface temperatures and subsequently warmed embankment fill materials down to 3.6‐m depth. Heat advection caused by the flow of subsurface water produced warming rates at depth in the embankment subgrade up to two orders of magnitude faster than by atmospheric warming (heat conduction). Subsurface water flow promoted permafrost thawing under the road embankment and led to an increase in active layer thickness. We conclude that the thermal stability of roadways along the Alaska Highway corridor is not maintainable in situations where water is flowing under the infrastructure unless mitigation techniques are used. Severe structural damages to the highway embankment are expected to occur in the next decade.

Thermal modeling of heat balance through embankments in permafrost regions

Permafrost is widely distributed in the northern hemisphere and permafrost degradation underneath transportation infrastructure is on-going due to many factors, such as climate change. The test site, constructed in 2008 along Alaska Highway at Beaver Creek, Yukon, Canada, provides valuable information on the long-term thermal response of permafrost underneath transportation infrastructure, to disturbances induced by constructions and climate change. The temperature data collected can also be used to calibrate thermal models to gain insight into relative effects of different factors on the sensitivity of the ground thermal regime underneath transportation infrastructure to on-going climate change. A finite-element, 2D heat conduction model, taking ice-water phase change into account, was developed based on the Beaver Creek experimental site characteristics and conditions. To increase the accuracy of the model, site-specific parameters, such as soil properties, near surface air temperature, and embankment dimension, were measured and used as input parameters. After calibration of the model, sensitivity analysis of certain input parameters, such as air temperature, embankment thickness and ground temperature, was conducted for different site conditions. The model was used to develop an engineering design chart allowing assessing the heat balance at the interface between embankment and natural ground. The heat balance analysis and the design chart are based on the results of sensitivity analysis and validated using the data from the Tasiujaq airstrip in Northern Quebec, Canada.

Alaska Highway Two-Step (by Caroline Woodward)

Book Review

Empirical test of the ClimateWNA model for local accuracy in the Kluane Lake area of the southern Yukon, Canada

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 75:111-115 (2018) - DOI: https://doi.org/10.3354/cr01511 NOTE Empirical test of the ClimateWNA model for local accuracy in the Kluane Lake area of the southern Yukon, Canada Charles J. Krebs1,*, J. David Henry2, Alice J. Kenney1, Elizabeth J. Hofer1 1Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver BC V6T 1Z4, Canada 2Kluane National Park and Reserve, Parks Canada, Haines Junction YT Y0B 1L0, Canada *Corresponding author: krebs@zoology.ubc.ca ABSTRACT: Ecological studies related to climate typically require data on temperature and rainfall. If local climate data are not available, the only recourse is to rely on data from the closest meteorological station or interpolated data from regional models of climate. In the southwestern Yukon, we have for the past 25 yr gathered ecological information such as counts of cones on white spruce trees and attempted to relate these biological variables to weather variables, thus requiring accurate climate information. From 2001 to 2014, we measured local summer temperature and rainfall during the growing season at 7 local sites along 250 km of the Alaska Highway and tested the accuracy of the ClimateWNA model estimates for these 7 sites as well as for the Haines Junction Environment Canada meteorological station. Monthly summer temperatures were reasonably well correlated with the predicted ClimateWNA values (r = 0.90, n = 299 mo), but summer rainfall was not (r = 0.37, n = 218 mo). We repeated this analysis with the Daymet climate model and got similar results. We caution the use of ClimateWNA or Daymet rainfall estimates for local areas in this part of the southwestern Yukon for the prediction of ecological measurements. KEY WORDS: ClimateWNA · Daymet · Temperature · Rainfall · Kluane · Yukon · Accuracy Full text in pdf format PreviousNextCite this article as: Krebs CJ, Henry JD, Kenney AJ, Hofer EJ (2018) Empirical test of the ClimateWNA model for local accuracy in the Kluane Lake area of the southern Yukon, Canada. Clim Res 75:111-115. https://doi.org/10.3354/cr01511 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 75, No. 2. Online publication date: May 17, 2018 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2018 Inter-Research.

Map of the Land, Map of the Stars

Before the highways, Yukon peoples freely travelled the rivers and trails, guided by the stars and their knowledge of the land. The play is about searching for our stories, gathering them, honouring them. It celebrates people’s deep connections between the land and the sky, which go back thousands of years for Yukon First Nations—the Indigenous people who lived here first. This play happens in many times and places. The audience time-travels back and forth with the seven performers to hear stories, songs, and dances from different times and people. This play explores how major events disrupted people’s way of life on the land. The Klondike Gold Rush was one. Thousands of stampeders came to the Yukon hoping to get rich. The building of the Alaska Highway during World War II brought more incredible changes to Yukon people. It also was very hard for the American soldiers who had to build it, many of them young African-American men. Some stories are about the colonization of Indigenous people: “the process where one group imposes its values and cultural beliefs on another group over time.” The laws, religions, and residential school system’s painful effects on families are part of these stories. The play also looks at how people come together in positive ways. Many fall in love with this land, and people already living here, and start new lives together. With this play, we’re trying to search for a good trail forward together, with reconciliation and harmony, for all of us.

Alaska Highway

Alaska Highway

Landslide susceptibility modelling using the quantitative random forest method along the northern portion of the Yukon Alaska Highway Corridor, Canada

The random forest method was used to generate susceptibility maps for debris flows, rock slides, and active layer detachment slides in the Donjek River area within the Yukon Alaska Highway Corridor, based on an inventory of landslides compiled by the Geological Survey of Canada in collaboration with the Yukon Geological Survey. The aim of this study is to develop data-driven landslide susceptibility models which can provide information on risk assessment to existing and planned infrastructure. The factors contributing to slope failure used in the models include slope angle, slope aspect, plan and profile curvatures, bedrock geology, surficial geology, proximity to faults, permafrost distribution, vegetation distribution, wetness index, and proximity to drainage system. A total of 83 debris flow deposits, 181 active layer detachment slides, and 104 rock slides were compiled in the landslide inventory. The samples representing the landslide free zones were randomly selected. The ratio of landslide/landslide free zones was set to 1:1 and 1:2 to examine the results of different sample ratios on the classification. Two-thirds of the samples for each landslide type were used in the classification, and the remaining 1/3 were used to evaluate the results. In addition to the classification maps, probability maps were also created, which served as the susceptibility maps for debris flows, rock slides, and active layer detachment slides. Success and prediction rate curves created to evaluate the performance of the resulting models indicate a high performance of the random forest in landslide susceptibility modelling.

Remote Mapping in Alaska's Wilderness: Accessing Resources in the Last Frontier

The rich, natural resources of Alaska have long been the focus of many pioneers seeking fortune in the Last Frontier. As captured in historical images of dedicated Klondike Gold Rush miners seeking their fortunes via the Chilkoot Trail, or the U.S. Army Corps of Engineers constructing the famous Alaska Highway, often the biggest challenge is getting there. Many of Alaska's resources are in remote locations where access can be limited. Given the distances that need to be covered, the difficult terrain to be crossed, and the number and type of unexpected users, remotely located resources are typically accessed via aircraft on remote landing strips. Isolated airfields are usually the least expensive and most cost-effective infrastructure to construct, making long-distance roads scarce in Alaska due to high construction and maintenance costs for long transportation corridors.

2016 Economic Developer of the Year Award Winners

Cando Economic Developer of the Year Award Winner Community Category Teslin Tlingit Council & Village of Teslin Teslin, Yukon is a century-old village located at mile 804 on the Alaska Highway. There is often a learning curve when partnering with others and sometimes the benefits of collaboration are overshadowed in order to fit within the rules and regulations in place by one funding body or another. Since that first joint venture, a steering committee was pulled together which resulted in the creation of a 10-year plan. Cando Economic Developer of the Year Award Winner Aboriginal Private Sector Business Category Birch Mountain Enterprises Ltd. After nearly a decade in business and over 250 employees, Birch Mountain Enterprises (BNE), is a proven and dependable fluid handling and steaming specialist in the Fort McKay area.

Debris flow susceptibility mapping using a qualitative heuristic method and Flow-R along the Yukon Alaska Highway Corridor, Canada

Abstract. This research activity aimed at reducing risk to infrastructure, such as a proposed pipeline route roughly parallel to the Yukon Alaska Highway Corridor (YAHC), by filling geoscience knowledge gaps in geohazards. Hence, the Geological Survey of Canada compiled an inventory of landslides including debris flow deposits, which were subsequently used to validate two different debris flow susceptibility models. A qualitative heuristic debris flow susceptibility model was produced for the northern region of the YAHC, from Kluane Lake to the Alaska border, by integrating data layers with assigned weights and class ratings. These were slope angle, slope aspect, surficial geology, plan curvature, and proximity to drainage system. Validation of the model was carried out by calculating a success rate curve which revealed a good correlation with the susceptibility model and the debris flow deposit inventory compiled from air photos, high-resolution satellite imagery, and field verification. In addition, the quantitative Flow-R method was tested in order to define the potential source and debris flow susceptibility for the southern region of Kluane Lake, an area where documented debris flow events have blocked the highway in the past (e.g. 1988). Trial and error calculations were required for this method because there was not detailed information on the debris flows for the YAHC to allow us to define threshold values for some parameters when calculating source areas, spreading, and runout distance. Nevertheless, correlation with known documented events helped define these parameters and produce a map that captures most of the known events and displays debris flow susceptibility in other, usually smaller, steep channels that had not been previously documented.

An albedo based model for the calculation of pavement surface temperatures in permafrost regions

High albedo road surfaces can be used to reduce the amount of heat absorbed by a pavement in order to limit the degradation of the permafrost under paved embankments. A model based on a simplified energy balance at the surface of a pavement is proposed to calculate the temperature of high albedo surfaces in order to assess their effectiveness. The model is validated using data from a test section built on the Alaska Highway near Beaver Creek, Yukon, Canada. The temperatures of four surfaces with different albedo were monitored for a year at the test section. The input data required for the model are the albedo of the surface, the incoming solar radiation, the air temperature and the wind speed. A set of design charts based on the radiation index and supported by the model are presented.