Description: The National Topographic Data Base (NTDB) comprises digital vector data sets that cover the entire Canadian landmass. Geomatics Canada has digitized and structured thousands of topographic maps, creating a complete and uniform product that can be highly useful in a broad range of industries. The NTDB includes features such as watercourses, urban areas, railways, roads, vegetation, and relief. The organizational unit for the NTDB is the National Topographic System (NTS), based on the North American Datum of 1983 (NAD83). Each file (data set) consists of one NTS unit at either the 1:50,000 or 1:250,000 scale. Furthermore, the data is now available by themes within a file. The ground data is depicted through points, lines, and areas.
Description: The National Topographic Data Base (NTDB) comprises digital vector data sets that cover the entire Canadian landmass. Geomatics Canada has digitized and structured thousands of topographic maps, creating a complete and uniform product that can be highly useful in a broad range of industries. The NTDB includes features such as watercourses, urban areas, railways, roads, vegetation, and relief. The organizational unit for the NTDB is the National Topographic System (NTS), based on the North American Datum of 1983 (NAD83). Each file (data set) consists of one NTS unit at either the 1:50,000 or 1:250,000 scale. Furthermore, the data is now available by themes within a file. The ground data is depicted through points, lines, and areas.
Description: This dataset represents the spatial distribution of terrain affected by active retrogressive thaw slumping for portions of Northwest Territories and Nunavut. Thawing of ice-rich permafrost can lead to significant terrain modification, alter terrestrial and aquatic ecosystems, and pose a threat to infrastructure. This remote mapping project contributes data on the distribution and density of thaw slumps across several study regions: Peel Plateau, Bluenose Moraine, Tuktoyaktuk Coast, and Banks Island study areas(Segal et al, 2016).All active retrogressive thaw slumps in the study regions weredigitised on-screen by viewing georeferenced imagery in Google Earth, ESRI ArcMap (versions 10.0 and 10.1), and the NWT Spatial Data Warehouse Geospatial Portal (http://www.geomatics.gov.nt.ca/sdw.aspx, NWT Centre for Geomatics 2013; Latitude Geographics Group Ltd.). Slumps were mapped using SPOT 5 and SPOT 4 imagery (10-metre resolution). However, Quickbird imagery (0.6-metre resolution) was also available in some parts of the study area. The imagery dated from 2006-2008. For Mackenzie Valley regions orthophotos with an effective pixel size of 0.5m and capture date of 2004 were used. Slumps were identified based on the presence of exposed sediments, poorly developed vegetation, and a well-defined headwall. Identified slumps were then consolidated into a single shapefile using ArcMap. Waterbodies were removed from the study area using CanVec hydro features (waterbody products; 1:50000 resolution) (Government of Canada 2016) prior to the slump density calculations (Segal et al. 2016)Data from the four reports (see credits) were conbined into this single dataset by Caslys in March 2017.
Copyright Text: Segal, R.A., Lantz, T.C., and Kokelj, S.V. 2016. Inventory of active retrogressive thaw slumps in the Peel Plateau, Northwest Territories. Northwest Territories Geological Survey, NWT Open Report 2015-020, 7 pages.
Segal, R.A., Lantz, T.C., and Kokelj, S.V. 2016. Inventory of active retrogressive thaw slumps on eastern Banks Island, Northwest Territories. Northwest Territories Geological Survey, NWT Open Report 2015-021, 8 pages.
Segal, R.A., Lantz, T.C., Kokelj, S.V., Brietzke, C.K., Reichheld, S., and Martin, A.F. 2016. Inventory of retrogressive thaw slumps in the Tuktoyaktuk coastlands, western Anderson Plain, and Mackenzie Delta region, Northwest Territories. Northwest Territories Geological Survey, NWT Open Report 2015-022, 9 pages.
Segal, R.A., Lantz, T.C., and Kokelj, S.V. 2016. Inventory of active retrogressive thaw slumps in the Bluenose Moraine, western Nunavut. Northwest Territories Geological Survey, NWT Open Report 2015-023, 8 pages.
Description: DESCIPTION: ESRI polygon type represents 15 x 15 km grid cells used to map retrogressive thaw slumps and data on relative slump density, based on NWT Open Report 2016-023 2.METHOD: Active retrogressive thaw slumps were mapped in a study area that included portions of the Yukon, Northwest Territories, and Nunavut, (study area of 1,274,625 km^2) using a 15 by 15 km grid system. GIS technicians assessed disturbance and landscape attributes for each grid cell by viewing georeferenced SPOT 5 and SPOT 4 orthomosaics from 2005-2010. Grid cells in the shape file have DENSITY attibute populated with values for 'mapped slump density' as follows: None, Low (1-5 slumps), Medium (6-14 slumps), High (15+ slumps), and NA(areas of water or bedrock terrain).ANALYSIS SUMMARY: Analysis was made at scales between 1:20 000 and 1:30 000, allowing mappers to confidently identify slumps as small as 0.75 ha. Stable slumps were not considered in this analysis because of challenges associated with consistently identifying stable, revegetated slump scars. As such, the mapping products derived using this methodology represent conservative estimates of slump distribution. A total of 615 grid cells, covering a total area of 138 365 km2 were identified as containing terrain influenced by thaw slumps. Most of the slump-affected grid cells (66%) were characterized as having a low density of active slumps, 24% by medium slump density and 10% by high slump density.PROJECTION: Canada Lambert Conformal Conic - reprojected from the original GNWT Lambert Conformal ConicATTRIBUTES:Shape_Leng - Perimeter of feature, in metres (Grid)Shape_Area - Area of feature, in metres squared (Grid)TYPE - The type of feature(Grid cell (15 x 15 km) for mapping retrogressive thaw slumps)DENSITY - Mapped slump density. None, Low (1-5 slumps), Medium (6-14 slumps), High (15+ slumps), NAREFERENCE - Reference to publication
Copyright Text: Segal, R.A., Kokelj, S.V., Lantz, T.C., Pierce, K.L., Durkee, K., Gervais, S., Mahon, E., Snijders, M., Buysse, J., and Schwarz, S., 2016. Broad-scale mapping of terrain impacted by retrogressive thaw slumping in Northwestern Canada. Northwest Territories Geological Survey, NWT Open Report 2016-023, 17 p.
Description: Comparitive and qualitative hydrocarbon potential maps have been published for the Dehcho, Sahtu, and Gwichin settlement areas. These works, in addition to similar mapping in the mainland part of the Inuvialuit Settlement Region, were combined to illustrate relative hydrocarbon potential in the Mackenzie Valley region of the Northwest Territories (NWT). This work was done in support of the NWT Protected Areas Strategy 5 year (2004-2009) Action Plan, to identify potential areas for conservation based on ecological value, in the Mackenzie Valley region (NWT PAS, 2003).
Copyright Text: Todd Slack of the NTGO office is thanked for providing technical advice, and Karen McFarlane is thanked for her editing skills. For further acknowledgements and references, please read the NWT Open Report 2005 - 004 Compiled Hydrocarbon Play Polygons for mainland NWT, published by the NWT Geoscience Office.
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