Mgis projects Clickable Collage

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MGIS Projects

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Ulrich Aeschlimann

  • In the context of global climate modifications, the monitoring of glaciers is a key instrument to quantify changes and to predict any resulting adverse impacts on alpine environments. This study examines data from the Revelstoke area (Glacier National Park, British Columbia) and the Kananaskis region (Peter Lougheed Provincial Park, Alberta) to address three issues that are paramount in any GIS-based, elevation model operations. The three modules of the study include: * Glacier parameter inventory, * DEM - Resolution considerations, * Climate Modeling. The glacier parameterization module extracts and compares elevation related factors (e.g., Mean elevation, ELA) as well as topographic parameters such as slope angles, aspect and curvature. The comparison of the glacier parameters of the two study areas indicates significant differences in the average glacier mean elevation and the average ELA. However, there is no statistical difference in average glacier area, length, shape index, and overall slope gradient between the two study areas. The second module, DEM resolution considerations, compares elevations extracted from different grid resolutions (30 m, 100 m, 200 m, and 500 m) to determine if certain parameters (e.g., mean elevation) are less problematic if obtained from low resolutions than other parameters, for example minimum and maximum elevations. The assessment shows that the average glacier mean elevation is similar (a maximum of 7 m difference) between values extracted from a 30 m grid and values extracted from a 500 m grid. However, the maximum and minimum elevations are considerably different between the 30 m and 500 m grids, particularly in the Kananaskis study area. As such, caution is recommended when using glacier parameters obtained from low resolution DEMs. In particular, grid resolutions of 500 m and larger may cause considerable errors in parameters measured. The third module, climate models for the two study areas, explores general ways of evaluating the role of climate under different climatic regimes. The chosen method includes extrapolation of 30-year data sets from climate stations using linear regression analysis. The climatic parameters assessed in this study are temperature and precipitation (i.e., snow depth). For the Revelstoke area, the temperature/elevation results indicate that there was a decrease of 0.53 °C in the mean July temperature with at every 100 m elevation increase (intercept 20.3 °C). The mean January temperature decreased by 0.48 °C at every 100 m elevation increase (intercept 8.4 °C). Due to a lack of alpine climate data in the Kananaskis area, the model was based on a constant gradient of 0.6 °C/100 m with intercepts of 22.3 °C for July and 11.4 °C for January. The intercepts were extrapolated from climate stations close to the study area. The Revelstoke data indicates an overall increase of 72 cm in snow depth per 100 m increase in elevation (intercept 89 cm). In the Kananaskis area the average increase in snow depth is 29 cm per 100 m increase in elevation (intercept 132 cm).
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  • Environmental controls on glacier distribution and the influence of spatial resolution of base data on terrain analyses

Adriana Aguilar

  • A computerized decision support tool implementing a multiple criteria evaluation approach using fuzzy set theory is programmed in Arc/Info as a prototype. To aid and evaluate lynx habitat selection in Southern Alberta by developing a surface of possibility, following three different approaches and comparing the results.
  • The prototype presented herein has been programmed in Arc/Info macro language (AML) following a modular approach and presented in a series of easy to use menus.
  • By combining geographic information systems (GIS) and multiple criteria evaluation (MCE) capabilities and in the context of analyzing geographic data the union of these methodologies appears to be instrumental in the design of efficient tools for spatial decision-making.
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Catherine Bow

  • Medical Cardiac Catheterization Data supplied from the APPROACH (Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease) database was reviewed and analyzed to determine the amount of error propagation inherent within the database. The error was found by comparing the address and postal code information in the database to the postal code and address information found in the 2001 Edition City of Calgary telephone book. A 16.32 percent error rate was found, excluding missed values and minor spelling errors. The database was corrected, postal code converted to find the longitude and latitude of the postal code, and geocoded into a GIS (Geographic Information Systems), namely ESRI’s ArcView 3.2. Two street network files were compared, the City of Calgary 2001 file and the Statistics Canada 1996 file. The address and postal code locations were found for both of these files in meters and subtracted. In SPSS (Statistical Package for Social Scientists), scattergrams and histograms were created to compare these two files. It was found that the Statistics Canada street network file was less accurate and had more errors within the database. The City of Calgary street network file was deemed to be very accurate as it was used and updated daily within the City. The subtraction of the address and postal code led to similar results in terms of the mean and standard deviation, but the Statistics Canada file created an unusually linear pattern at the 25 and –25 meter x and y-axis. This linear pattern is due to the block-face representative postal code point location of 20 meters from the centre of the street. Depending on the application, the postal code was deemed to be a fairly good representation of the address location.
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  • A GIS Based Study of Address and Postal Code Location and Street Network Files and their use in Medical Geography Research

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