Analysis

 

Introduction

Objectives

Methodology

Analysis

Error Issues

Results

 

Unfortunately our DEM could not be used for what we had hoped to achieve, as the data set could not be used to perform drape procedures with the digitized coverages and for elevation analysis.  For the drape to occur, the DEM and the digitized coverages had to be raster and in the same data type, which was not the case in this project. The original IEE4bytereal DEM data type was subsequently changed to 32-bit integer GEOTIFF upon importation into Idrisi.  Consequently, by changing the DEM data type, all of the crucial elevation data needed for the basis of our project analysis was lost. Elevations could thus not be queried and correlated to paleohydrology features in the digitized map.

Drainage network analyses relating the region’s post-glacial landscapes and hydrology drainage patterns could not be done without the elevation data.  Some parameters such as the x-y DEM (converted into 32-bit integer) coordinates were unknown and some drainage analysis procedures could not be carried out due to the lack of computer hard drive space.  We were also unable to complete the watershed analysis of the area.  A watershed analysis combined with the planned runoff analysis may have been able to determine the full drainage basin of the Southern Alberta area.  From this drainage basin, general channel flow directions and patterns could be analyzed and correlated to the glacial landscape.

Using the DEM as a visual interpretation aid, one of the goals was to see whether the drainage system and watersheds had been created by the Laurentide glacial events through its advance and more likely, its recession and formation of vast outwash plains and glacial lakes.  Some types of geology of weaker resistance are more susceptible to glacial change than others, enabling ice sheets to carve new drainage networks and alter existing ones.  Our analysis would have shown where the present drainage network is and how it fits in with the glacially formed, topographic landscape. The DEM might have provided another visual viewpoint for looking at misfit river channels flowing in large, broad, former glacial outwash spillways that were formed during ice sheet recession.  Further, the drainage network would have aided in our analysis of the origin of the glacial lakes.  For example, lake sediments not associated with, or in the proximity to adequate drainage may suggest that these lakes were sub-glacial in origin.

In short, the key to our analyses lies in the elevation data of the DEM.  Unfortunately, due to technical difficulties regarding the DEM, these were not solved.  These problems included: loss of elevation data, shape incompatibilities, and insufficient time to solve these problems.  

The only analysis we were able to do with the remaining digitized Alberta dataset was in determining the location of paleohydrology lacustrine and fluvial sediments in Alberta.