Date of Graduation

12-2023

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Geosciences (PhD)

Degree Level

Graduate

Department

Geosciences

Advisor/Mentor

Jackson Cothren

Committee Member

Theiss, Henry

Second Committee Member

Shaw, John

Third Committee Member

Warn, Seth

Keywords

Arctic, change detection, digital elevation model, historic imagery, photogrammetry

Abstract

In a rapidly changing Arctic, reconstructing landscapes pre-warming is essential to understanding impacts due to climate-inducted geomorphic change. High-latitude elevation datasets extend temporally back to the 2000s, while region-wide warming became measurable in the 1980s. Historic aerial imagery archives provide datasets of high-resolution imagery from the mid- to late- 1900s with stereo-capability that can be harnessed to create historic digital elevation models, or hDEMs. A major issue with reconstructing a surface from the past is finding a way to constrain it in space, given a lack of ground control from that era, especially at high latitudes. The main purpose of this study was to determine if an hDEM could be used to detect altimetric change in an area of poor ground control. I developed an hDEM from historic aerial imagery over the Black Mountain alluvial fan complex in NT, Canada, and used satellite imagery-derived ground control points to constrain the model in space. The resulting hDEM qualitatively and quantitatively displayed geomorphic realism, with few interpolation artifacts along the model edges, over water surfaces, and in places of shadows. When compared with the ArcticDEM, the hDEM displayed a vertical RMSE of 5.19m. I was able to isolate approximately 30-40m of altimetric change from a landslide (c.2013-2016) in the Black Mountain Fan catchment, supporting the supervised use of hDEMs for change detection studies.

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