Introducing a cost-effective method to assess beach-dune dynamics using existing infrastructure

Abstract

Coastal storms can induce significant geomorphic change often leaving behind costly erosion projects for local communities. Existing methods for quantifying geomorphic change (i.e., total stations, airborne and terrestrial LiDAR systems, drones) are often cost prohibitive. These methods often require considerable pre-planning, which often prohibits making data collection related to sudden events. The objective of this study is to introduce the applicability of repurposing existing signs as erosion pins to measure morphologic change along a barrier island. To demonstrate the applicability of this method, this novel methodology was tested along the Isle of Palms, SC after the passage of Hurricane Irma. Prior to the storm, an extensive foredune inventory was completed utilizing a GPS camera. Signs along the beach-dune system were photographed generating 70 data points and creating a comprehensive geospatial monitoring network. Post-storm, 56% of the signs remained and the foredunes experienced up to 2.5 m of erosion. The remaining signs and foredunes we re-photographed and compared in juxtaposition with pre-storm photos to measure relative geomorphic change at each data point. This method provides coastal community officials the capability to measure erosion-accretion dynamics on a limited budget utilizing existing infrastructure. While this method was tested in South Carolina, it shows promise of universal application to any coastal community.