RATES OF SHORELINE CHANGE ON THE NORTH CENTRAL BASIN OF LAKE ERIE

Coastal erosion is an increasing issue in the Laurentian Great Lakes due to changes in the frequency and magnitude of storm activity, fluctuating lake levels, and the decrease in protective lake ice. The coastal bluffs in Lake Erie have been retreating at an average end point rate of -0.8 m/y between 1909 to 2018, leading to the closure of many roads close to the shoreline as well as properties and infrastructure collapsing into the lake. Due to the absence of aerial imagery prior to the 1950s and a lack of high-quality imagery up until the early 2000s, a comprehensive analysis of bluff erosion was conducted utilizing the Southwestern Ontario Orthophotography Project (SWOOP) imagery and digital elevation model dataset for 2006, 2010, 2015, and 2020. By digitizing the bluff brink, bluff toe, and shoreline for each year in the area between Rondeau and Long Point Provincial Parks, accurate estimates of both erosion, accretion, and the volumetric loss of bluff material to the lake were made for this changing shoreline. Alongshore variation of rates can be attributed to the influence of the structural control that jetties and other coastal infrastructure create by disrupting the transport of sediment within the littoral cell. Increased lake levels as well as diminished protective lake ice indicate that wave erosion at the base of the bluffs is the primary mechanism of sediment loss on this northern shoreline.