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Moving at a glacial pace: a biogeomorphological analysis of ecological succession in recently deglaciated terrain in the Selkirk Range, BCLincoln, Astra 02 May 2022 (has links)
This research developed a novel workflow for combining different types and scales of data to understand the development of small, steep, and sheltered glacial forefields across space and time using the Avalanche glacier of the Selkirk Range, BC as a case study. As glaciers recede, symbiotic geomorphological and ecological feedback loops determine the ecological succession in recently deglaciated terrain, which can in turn effect landform stability and water quality downstream. In order to describe emergent land cover patterns in the forefield, this research uses Corenbilt’s (2007) fluvial biogeomorphic succession (FBS) framework to interpret a century of land cover changes. To do so, an experimental protocol was developed that combined remotely sensed data – repeat photographs, historic air photographs, satellite imagery, and digital elevation models – and data collected in-situ using a photo transect method. Analysis of more than a century of photographs determined that the Avalanche glacier is receding at a slower rate than has been observed in the region’s larger glaciers, subsequently leading to a slower rate of forefield habitat expansion. Still, all four stages of fluvial biogeomorphological succession were found across the Avalanche glacier’s forefield. It was found that in the Avalanche forefield, terrain age seems to place a limit on which successional stage is possible at any given location within the forefield, but topographic features like slope angle seemed to influence succession patterns within areas that had the same terrain age. Further research is needed to see whether these findings are consistent for similar steep, small, and sheltered glaciers in the region. / Graduate
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When the flame goes out: an exploration of landscape change using repeat photography related to Indigenous burning in Kananaskis Country, AlbertaFrederickson, Maya 02 May 2022 (has links)
Fire exclusion has defined 20th century forestry practices in North America and produced many unintended consequences. In the Canadian Rocky Mountains, the removal of fire from the landscape caused significant landscape changes over the past century. Mountain forests are now more uniform in stand composition and structure, and understorey diversity is reduced. These changes mean that forests are now more susceptible to high-intensity, difficult-to-control wildfires. Re-introducing Indigenous led historical burning patterns modeled on traditional burning techniques can be a restoration technique for these highly altered ecosystems. Indigenous fire regimes that emphasized regular, low-intensity burning created forests that had less fuel build up and were not as susceptible to dangerous wildfires. In order to effectively re-introduce historical fire regimes onto the Canadian mountain landscapes, it is essential to understand the history of human management of landscapes with fire.
This project uses new methods of oblique image analysis that build on recent developments in oblique image analysis to examine the historical management of a portion of the traditional territory of the Stoney Nakoda Nation that overlaps present day Kananaskis Country in Alberta, Canada. While it is difficult to capture low-intensity Indigenous burns using traditional fire reconstruction methods, in-depth analysis of historical photos taken before the introduction of fire suppression laws may reveal new insights into historical fire regimes. Images were classified using machine learning software and compared to images classified by a human to verify the accuracy of the machine learning software. A case study of georeferencing images was also conducted, with the landcover estimates generated by georeferenced images compared to oblique estimates. Spatial signatures of Indigenous burning were identified and applied to repeat image sets to look for visual evidence of Indigenous burning on the landscape. The results from this study provide a useful starting point for further research into repeat photography and Indigenous burning. / Graduate
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Feature-based matching in historic repeat photography: an evaluation and assessment of feasibility.Gat, Christopher 16 August 2011 (has links)
This study reports on the quantitative evaluation of a set of state-of-the-art feature detectors and descriptors in the context of repeat photography. Unlike most related work, the proposed study assesses the performance of feature detectors when intra-pair variations are uncontrolled and due to a variety of factors (landscape change, weather conditions, different acquisition sensors). There is no systematic way to model the factors inducing image change. The proposed evaluation is performed in the context of image matching, i.e. in conjunction with a descriptor and matching strategy. Thus, beyond just comparing the performance of these detectors and descriptors, we also examine the feasibility of feature-based matching on repeat photography. Our dataset consists of a set of repeat and historic images pairs that are representative for the database created by the Mountain Legacy Project www.mountainlegacy.ca. / Graduate
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A century of landscape-level changes in the Bow watershed, Alberta, Canada, and implications for flood managementTaggart-Hodge, Tanya 09 December 2016 (has links)
This study used a comparison of one hundred and forty-eight historical (1888-1913) and current (2008-2014) oblique photographs from thirty-two stations to identify land cover changes that have occurred in portions of the Bow and Elbow valleys as well as surrounding Kananaskis Country region. Implications of these changes for flooding and flood management were explored. Forest cover was found to have drastically increased over the past century, particularly in the Bow valley, as did areas of direct human development. In the same time period, grasslands increased in the Elbow valley but decreased in the Bow, while regenerating areas decreased uniformly throughout both valleys. An analysis of pre (2008)-and-post (2014) flood conditions demonstrated no change in coniferous forest cover in both valleys over the 6-year period, but uncovered a decline of 20% in the Elbow and 3% in the Bow in the broadleaf/mixedwood category. The Elbow’s channel zone was larger in 2014 compared to 2008, whereas the extent of the Bow’s channel zone remained constant. However, both the Bow and Elbow’s bare exposed bars increased substantially, most likely as a result of the 2013 flood. The major source of water flows that contributed to the 2013 flood event originated in high elevation rock and scree areas, which, unlike floodplains, are elements of the watershed that cannot be manipulated over time. It is now recognized that forest cover should act as a buffer to floods. Nevertheless, the 2013 flood event occurred despite the massive buffering effect of a huge increase in older forest stands across the study area. The final discussion includes recommendations for improving flood management in the area. / Graduate / 0329, 0768, 0478 / tanya.taggarthodge@gmail.com
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