Coastal Geomorphic Change Due to Shoreline Protections – A Study on Lake Michigan’s Eastern Shoreline

Keywords: UAS, remote sensing, coastal geomorphology
Session Type: Virtual Paper Abstract
Day: Monday
Session Start / End Time: 2/28/2022 03:40 PM (Eastern Time (US & Canada)) - 2/28/2022 05:00 PM (Eastern Time (US & Canada))
Room: Virtual 39

Abstract

Lake Michigan’s water level has been above average every month of the year since 2015. Water level and waves are causing major erosion along the shore of Lake Michigan. The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has characterized a majority of Michigan’s western shoreline as high risk for erosion. Shoreline protections are an attempt by property owners to reduce the landward erosion of their property. Hard and permanent structures, such as seawalls, have been the method of choice by many homeowners. Seawalls though can negatively impact wildlife and the water quality. Moreover, seawalls can affect adjacent beaches with the ‘end-wall’ effect by redirecting wave energy downdrift. This study plans on using an unoccupied aerial system (UAS)-collected low altitude aerial imagery and Structure from Motion (SfM) photogrammetry to produce high-resolution three-dimensional surveys of Hagar Beach in Hagar Township, Michigan- that is adjacent to a seawall. Data were collected biweekly from March to November in 2021 to explore short-term geomorphology change. Shoreline positions were digitized (two-dimensional) and volumetric (three-dimensional) differences were calculated showing that the seawall has an influence of about 200ft on the adjacent beach.