Authors: Elizabeth George*, University of Windsor
Topics: Coastal and Marine, Geomorphology, Earth Science
Keywords: Erosion, Foredune, Recovery, Beach-dune
Session Type: Virtual Paper
Start / End Time: 4:40 PM / 5:55 PM
Room: Virtual 45
Presentation File: No File Uploaded
Coastal foredunes provide protection to ecosystems, infrastructure, and recreational areas from storm waves and surge. Future climate uncertainty such sea level rise and increase in major storm frequency amplifies the demand to address inconsistencies in morphological definitions, in order to accurately compare pre- and post-storm morphology of a system and predict its response to future storm events. Parameters such as dune height and volume are dependent on the location of the beach-dune transition zone (dune toe), and their variability can greatly affect the accuracy of storm impact prediction models. There are currently multiple methods to delineate the dune toe such as the inflection point, relative relief, least cost pathway, and polynomial, each of which are subject to some form of user interpretation bias. The purpose of this study is to compare the effectiveness of current dune toe extraction techniques for monitoring a recovering dune system and evaluate how these extractions relate to beach-dune interaction processes. The cross-shore positional frequency of dune building and erosion processes such as wave run up, sediment transport, vegetation extent, were monitored at the recovering study site of Brackley Beach, Prince Edward Island, Canada following the damage of Extra-Tropical Storm Dorian. Monitoring objectives include identifying an objective dune toe extraction technique that encompasses process interaction between the beach and dune. Validity of the process-based definitions of the dune toe are tested by comparing surveyed pre- and post-storm volumetric change with modelled volumetric change using XBEACH.