scholarly journals Shaded-relief digital elevation model, Babine Porphyry Copper District (NTS 93 L/NE, M/SE), British Columbia

2001 ◽  
Author(s):  
C Lowe ◽  
J K Porter ◽  
V M Levson ◽  
D G MacIntyre
Keyword(s):  
British Columbia ◽  
Digital Elevation Model ◽  
Porphyry Copper ◽  
Digital Elevation ◽  
Elevation Model ◽  
Shaded Relief

scholarly journals A new method for deriving glacier centerlines applied to glaciers in Alaska and northwest Canada

2013 ◽  
Vol 7 (5) ◽  
pp. 5189-5229
Author(s):  
C. Kienholz ◽  
J. L. Rich ◽  
A. A. Arendt ◽  
R. Hock
Keyword(s):  
British Columbia ◽  
Digital Elevation Model ◽  
Average Length ◽  
Length Change ◽  
New Method ◽  
Length Ratio ◽  
Branch Order ◽  
Digital Elevation ◽  
Glacier Length ◽  
Elevation Model

Abstract. This study presents a new method to derive centerlines for the main branches and major tributaries of a set of glaciers, requiring glacier outlines and a digital elevation model (DEM) as input. The method relies on a "cost grid – least cost route approach" that comprises three main steps. First, termini and heads are identified for every glacier. Second, centerlines are derived by calculating the least cost route on a previously established cost grid. Third, the centerlines are split into branches and a branch order is allocated. Application to 21 720 glaciers in Alaska and northwest Canada (Yukon, British Columbia) yields 41 860 centerlines. The algorithm performs robustly, requiring no manual adjustments for 87.8% of the glaciers. Manual adjustments are required primarily to correct the locations of glacier heads (5.5% corrected) and termini (3.5% corrected). With corrected heads and termini, only 1.4% of the derived centerlines need edits. A comparison of the lengths from a hydrological approach to the lengths from our longest centerlines reveals considerable variation. Although the average length ratio is close to unity, only ~ 50% of the 21 720 glaciers have the two lengths within 10% of each other. A second comparison shows that our centerline lengths between lowest and highest glacier elevations compare well to our longest centerline lengths. For > 70% of the 4350 glaciers with two or more branches, the two lengths are within 5% of each other. Our final product can be used for calculating glacier length, conducting length change analyses, topological analyses, or flowline modeling.

scholarly journals Digital elevation model, Nechako River, British Columbia

2001 ◽  
Author(s):  
C Lowe ◽  
V M Levson ◽  
L C Struik ◽  
A Plouffe ◽  
R G Anderson ◽  
...  
Keyword(s):  
British Columbia ◽  
Digital Elevation Model ◽  
Digital Elevation ◽  
Elevation Model

scholarly journals A new method for deriving glacier centerlines applied to glaciers in Alaska and northwest Canada

2014 ◽  
Vol 8 (2) ◽  
pp. 503-519 ◽  
Author(s):  
C. Kienholz ◽  
J. L. Rich ◽  
A. A. Arendt ◽  
R. Hock
Keyword(s):  
British Columbia ◽  
Digital Elevation Model ◽  
Average Length ◽  
Length Change ◽  
New Method ◽  
Length Ratio ◽  
Branch Order ◽  
Digital Elevation ◽  
Glacier Length ◽  
Elevation Model

Abstract. This study presents a new method to derive centerlines for the main branches and major tributaries of a set of glaciers, requiring glacier outlines and a digital elevation model (DEM) as input. The method relies on a "cost grid–least-cost route approach" that comprises three main steps. First, termini and heads are identified for every glacier. Second, centerlines are derived by calculating the least-cost route on a previously established cost grid. Third, the centerlines are split into branches and a branch order is allocated. Application to 21 720 glaciers in Alaska and northwest Canada (Yukon, British Columbia) yields 41 860 centerlines. The algorithm performs robustly, requiring no manual adjustments for 87.8% of the glaciers. Manual adjustments are required primarily to correct the locations of glacier heads (7.0% corrected) and termini (3.5% corrected). With corrected heads and termini, only 1.4% of the derived centerlines need edits. A comparison of the lengths from a hydrological approach to the lengths from our longest centerlines reveals considerable variation. Although the average length ratio is close to unity, only ~ 50% of the 21 720 glaciers have the two lengths within 10% of each other. A second comparison shows that our centerline lengths between lowest and highest glacier elevations compare well to our longest centerline lengths. For > 70% of the 4350 glaciers with two or more branches, the two lengths are within 5% of each other. Our final product can be used for calculating glacier length, conducting length change analyses, topological analyses, or flowline modeling.

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