SHORELINE EROSION RELATED TO SEA-LEVEL RISE AND CHANNEL MIGRATION ON LITTLE CUMBERLAND ISLAND, GEORGIA

Little Cumberland Island (LCI) is a barrier island on the southern Georgia coast. The island is accessible only by boat and development has been limited to small dirt roads that lead to ~40 houses. The residents on LCI have experienced increased flooding and shoreline erosion over the past decade which has impeded their access to the roads and dock, commonly stranding them in their homes for multiple days. On LCI, erosion has been exacerbated by sea-level rise and the migration of tidal channels. Residents are concerned about their community resilience and their longevity of their time remaining on the island. To predict the longevity of modern roads and houses, historic satellite imagery in Google Earth Pro was used to survey the position of the coastline during ten dates from 1988 to 2019. Trends in historic erosion rates were then calculated and future erosion rates up to the year 2029 were predicted using linear regression. Shoreline erosion varied spatially, with the most extreme erosion rates measuring ~10 m/year over the past 31 years. The estimated projections indicate that while much of the road will not be directly impacted by marsh erosion over the next decade, the shoreline will likely erode into a small section of road cutting off access to >10 houses. Additionally, the severity and frequency of periodic tidal and storm flooding will increase along this road as the marsh buffer continues to diminish. The residents of Little Cumberland Island wish to keep the island as natural as possible so options to address this issue are limited. Other barrier islands facing an increased flooding risk have initiated several strategies to mitigate coastal erosion, including armored dunes, increased dune vegetation, and human-made overwash funnels. To maintain reasonable access to LCI over the coming decades, homeowners will likely be unable to continue relying on natural coastal structures and may instead have to turn to more intense coastal engineering.