Changes in Lake Michigan bluff recession rates over time were evaluated by comparing rates derived from a study done in the 1970s (Buckler 1981) to modern rates (since the 1970s) generated by data collection for this thesis. A subset of the 118 original sites were mapped, totaling 17 bluff sites along the Michigan coast of Lake Michigan. Modern rates were calculated through field RTK-GPS surveys and digitizing bluff crests from historical aerial imagery. Recession rates were correlated to various site morphologic and hydrodynamic variables to assess their role in facilitating change over space and time. Major conclusions of this study are: (1) no tested variables correlated well with morphologic or hydrodynamic variables, and thus cannot explain the large spatiotemporal variability in recession rates along the MI coast, (2) more focus should be paid to quantifying and understanding the coupled changes at the bluff toe and crest, to better constrain the 3-D geomorphic recession patterns of Great Lakes bluffs, and as processes driving recession at the bluff toe could not be meaningfully correlated to recession rates, (3) utilizing digitized bluff crest locations from georeferenced aerial imagery to derive bluff recession rates introduces errors associated with human interpretation that can be overcome now with geospatial technologies including RTK-GPS, LIDAR, and sUAS (i.e. drones), and (4) as small-scale processes appear to play an important role in driving recession, more attention should be given toward documenting small-scale changes in recession and processes at individual sites, and to avoid over-generalization of the dynamic geomorphic environment.
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