Authors: Ethan Theuerkauf*, Michigan State University, Katherine N Braun, University of Illinois at Urbana-Champaign, Francis K Wiese, Stantec Consulting Services
Topics: Coastal and Marine, Geomorphology, UAS / UAV
Keywords: coastal geomorphology, erosion, habitat loss, Great Lakes
Session Type: Paper
Presentation File: No File Uploaded
Coastal erosion in the Great Lakes causes beach and bluff recession, infrastructure damage, and habitat loss. Direct economic impacts of erosion, such as property damage, are often quantified along coastal regions in order to prioritize management actions. Habitat loss commonly occurs in response to coastal erosion, yet is rarely quantified and placed into a framework that allows prioritization alongside economic factors. This step is imperative in order to balance economic and ecologic priorities and identify stretches of shoreline to protect with limited management resources. This study puts forth a framework that links coastal morphodynamics, habitat loss, and ecosystem value in order to identify priority coastal management sites. The framework is tested at a rapidly eroding sandy beach system along the western coast of Lake Michigan.
Monthly aerial imagery (July 2018 through July 2019) were collected at four sites immediately adjacent to the shoreline along Illinois Beach State Park with a small-unoccupied aerial system. Areas of different coastal habitat types were digitized in the images and then used to quantify areal habitat change between each time step. These habitat changes were then linked to the probable physical drivers, such as beach and nearshore morphodynamics, fluctuating water levels, storm events, and human disturbance. These linkages between drivers and responses of habitat change were combined with a habitat-specific ecosystem service valuation to generate a vulnerability ranking for each site. Highly vulnerable sites have high value ecosystems that are threatened by erosion and should be the priority of coastal management.