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TitleSeasonal surface displacement and highway embankment grade derived from InSAR and LiDAR, Highway 3 west of Yellowknife, Northwest Territories
LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorStevens, C W; Short, NORCID logo; Wolfe, S AORCID logo
SourceGeological Survey of Canada, Open File 7087, 2012, 112 pages; 1 DVD, Open Access logo Open Access
PublisherNatural Resources Canada
Documentopen file
MediaDVD; on-line; digital
File formatreadme
File formatpdf; rtf; shp; xml
ProvinceNorthwest Territories
NTS85J/07; 85J/10; 85J/11
AreaYellowknife; Great Slave Lake
Lat/Long WENS-115.3333 -114.4167 62.7000 62.3833
Subjectssurficial geology/geomorphology; engineering geology; geophysics; Nature and Environment; satellite imagery; mapping techniques; displacement; construction capability; construction suitabilities; permafrost; freezing ground; ground ice; terrain sensitivity; terrain types; arctic geology; InSAR; LiDAR
Illustrationslocation maps; photographs; cross-sections; tables; satellite images; plots
ProgramClimate Change Geoscience
Released2012 05 16
AbstractMonitoring highway conditions is critical to effectively maintain northern infrastructure within discontinuous permafrost environments. This Open File presents seasonal surface displacement and embankment grade calculated for a 48 km section of Highway 3 (km marker 282 to 330), located to the west of Yellowknife. Satellite interferometric synthetic aperture radar (InSAR) was used to calculate relative surface displacement from May to September of 2010 along the highway corridor. Airborne light detection and ranging (LiDAR) data acquired on August 22 and 24, 2010 were also used to measure road elevations, calculate embankment grade and map raised ice-rich clay terrain. The highway embankment was determined to be seasonally stable over 67% (31.2 linear km) of the 48 linear kilometres analyzed, which corresponds to sections where bedrock is exposed or covered by a thin veneer of sediment. Low downward displacement (-1 to -3 cm) was calculated over 20% (9.3 linear km) and moderate downward displacement (-3 to -6 cm) over 2% (1.0 linear km) of the highway. Downward displacement is attributed to subsidence that occurs across forested clay and peatland terrain. Over an additional 11% (4.9 linear km) of the highway, displacement was not measured due to incoherence between repeat satellite observations. Incoherence over the highway is primarily attributed to the smooth surface of the roadway that produces very low radar return (i.e. low signal strength). At one location where the highway crosses the former location of an ice-rich clay ridge, the embankment has subsided by 95 cm over a 4-5 year period following construction. Embankment side slopes were determined to be steeper than recommended grade along some sections where highway instability exists. LiDAR intensity is also shown to be successful for mapping wet terrain that may thermally impact permafrost. The derived data products accompanying this Open File are presented in the form of graphical representations and digital geotiff and shapefiles compatible with ArcGIS. The datasets demonstrate the ability to remotely monitor several aspects of highway infrastructure located within the discontinuous permafrost zone and to identify sections of the highway that may require future remediation and adaption measures.

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