Using Unmanned Aerial Vehicles and "Structure from Motion" Software to Monitor Coastal Erosion in Southeast Florida

of a thesis at the University of Miami. Coastal Erosion poses a significant threat to several coastal communities in Florida. Ecosystem managers are tasked with both protecting the community from storm events and preserving the natural ecosystems found in the coastal zone. The most widely utilized method for shoreline protection in Florida is beach renourishment. Beach renourishment projects are difficult to track with regularity because the methods used to monitor and measure coastal erosion are cost-prohibitive. Current methods of coastal erosion tracking include Terrestrial Laser Scanning, airborne-Light Detection and Ranging (LiDAR) scans, and Real Time Kinematic Global Positioning Surveys. These methods are time consuming and resource intensive. Unmanned Aerial Vehicles are gaining popularity amongst both the public and researchers, and could offer a cheaper alternative to airborne-LiDAR. Coupled with " Structure from Motion " software, UAVs can track coastal erosion along stretches of beach on a more frequent basis. UAVs are also better suited to react to storm events to investigate how the coast was impacted in the immediate aftermath. This thesis found that UAVs are both feasible and cost-effective when used in this context. The major limiting factor involved was the GPS device used. " Structure from Motion " technology proved to be accurate within this context. Agisoft PhotoScan Pro was used to develop 3 dimensional models of the beach ecosystem " scene ". Digital Elevation Models (DEM) were then generated using z-values and known positions of Ground Control Points (GCP). The geo-referenced DEM was then imported into ESRI's AcrGIS, where it was compared to previously-generated DEMs using the Raster Calculator tool. This method allowed for easy visualization of erosion along the coastline. While the data proved to be useful in qualitative analysis, the accuracy of the GPS used in this study prevents the results from being used in a quantitative function. With accurate GPS, such as Real Time Kinematic GPS which has sub-centimeter level accuracy, this method could produce survey-grade DEMs and be a feasible alternative to LiDAR.