Mountain and Glacier Mapping Cartographic Depiction and Visualisation of Alpine Glacier Changes in Western Canada Roger Wheate University of Northern British Columbia, Prince George, BC, Canada
[email protected] ABSTRACT boundary associated with slow regrowth on former ice- covered surfaces (Figure 1). Mountain cartography involves standard design issues including generalization and symbolization of topo- The earliest mountain topographic mapping series graphic features, but there are additional challenges was the Interprovincial Boundary Commission Sur- when those features show ongoing change. Contin- vey (IBCS) which covered the boundary region in 54 ued warming over the last since ~1980 has generated maps between 1903-1924. Before aerial photography the need to visualize series of past and present glacier became widely available after 1945, such mapping was configurations in high mountain landscapes. We have accomplished by photo-topography, a technique using collected multiple datasets for glacier extents and multiple oblique views captured from terrain view- elevation surfaces which date as far back as the early points and pioneered by Edouard Deville, Surveyor decades of the 20th century, mostly from topographic General of Canada (1885–1924). One of the best mapping and satellite imagery. They enable a series known practitioners was surveyor- alpinist Arthur O. of cartographic representation methods that include Wheeler, who was also co-founder of the Alpine Club overlaying multiple ice extent vectors, usually on a of Canada (Wheeler, 1920). Federal mapping acceler- contemporary satellite image base. The sequence of ated after 1945 although it took almost 50 years more Digital Terrain Models (DTMs) can be combined to to complete the mapping of the provinces at 1:50,000 generate isarithmic images depicting ice downwasting, scale.