CGRG Bibliography of Canadian Geomorphology
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Author : Ball, D.G.A.
Date : 1995
Title : Methods for detecting and outlining subglacial meltwater erosion features in the Dollard region of southwestern Saskatchewan.
Publication : Unpublished Masters thesis. Queen's University, Kingtson
Issue :
Page(s) : 103 p.
Abstract
About 12000 years ago, glaciers retreating from southwestern Saskatchewan left behind a thin veneer of glacial till which covered most of the region, apart from locally concentrated subglacial meltwater erosion features (SMEFs), formed by high energy, high volume flows of meltwater beneath the glaciers. A suite of these features is found on the southern Swift Current Plateau near the small town of Dollard. This thesis investigated methods for finding and outlining SMEFs, using the Dollard region to test the methods. A digital elevation model (DEM) was created for the Dollard region using aerial photography and the microcomputer based DigitalVideo Plotter (DVP). The edge of any landscape depression (LD), including a SMEF, is defined as the locus of points surrounding the LD which have maximum positive (convex) curvature. Two methods for finding and outlining this edge in a DEM were developed. The first involved calculating the slope at each DEM node and plotting a slope vector map. The second, more objective method requires direct calculation of the curvature for each DEM node. A SMEF map for the Dollard region, created by these methods, showed SMEF orientations indicative of a northeastern source for the meltwater that created them. An overlay of a map of all LDs in the Dollard region onto the soil map revealed that soils in LDs tend to be more saline, less well drained and of poorer agricultural rating. Thus, finding LDs provides a simple method for identifying problem soils. Alternately, the relationship of certain soil properties with LDs provides a technique for locating LDs in other regions.
Bibliography of Canadian Geomorphology