CGRG Bibliography of Canadian Geomorphology
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Author : Chasmer, L.; and Hopkinson, C.
Date : 2001.
Title : Using Airborne LASER Altimetry and GIS to assess scale-induced radiation loading errors in a glacierised basin.
Publication : Proceedings of the Fifty-Eighth Annual Eastern Snow Conference May 17 –19,2001 Ottawa, Ontario, Canada
Issue :
Page(s) : 60-70.
Abstract
Short-wave radiation received over a surface is a major determinant of both the local meteorology and the amount of melt that a snow or ice surface may undergo. However, when applying radiation models to raster surfaces we find that the grid resolution has a marked effect on the radiation load over a given area. For example, a radiation loading model applied to a 25m resolution digital elevation model (DEM) will not account for surface textures smaller than the actual pixel size. By applying a radiation loading model to a higher resolution DEM, we are able to account for such textural considerations as local shadowing, slope and aspect. In this study high resolution data has been obtained from an airborne scanning LASER altimetry survey of Peyto Glacier and the Wapta Icefields in the Canadian Rockies. The LASER altimetry data, surveyed by Optech, Inc., has been gridded to 2.5 m and 25 m resolutions for this comparative study. The purpose of this study is to compare the results of a short-wave radiation loading model of energy flux density (W m -2 ) applied over a 25-metre DEM and a 2.5-metre DEM of Peyto Glacier in the Canadian Rocky Mountains. The results of this study illustrate that radiation load is primarily influenced by terrain slope, which reduces radiation load upon a surface by between 1 and 6 W m -2 as derived from the higher resolution DEM. Texture has also been examined using Landsat TM data of the study area.
Bibliography of Canadian Geomorphology