A Framework for Using Coastal Monitoring Data: A Foredune Case Study

To support coastal practitioners and decision makers manage the complex coastal zone a structured framework was developed to navigate a range of technologies, datasets and data-derived products based on their suitability to monitor the spatial and temporal diversity of coastal processes and morphological indicators. Remote piloted aircraft (RPA) fitted with a LiDAR sensor was used in conjunction with airborne LiDAR and photogrammetry data to undertake foredune change analyses for selected sites in southeastern Australia to validate and demonstrate optimal technology for coastal monitoring. Results were compared with satellite derived coastal change products, including the Digital Earth Australia Coastlines and CoastSat. Foredune volumes from the mid-1900s to 2024 at the highly modified and urbanised Woonona-Bellambi and Warilla Beaches exhibited long-term stability interrupted by large storm events and anthropogenic interventions. Satellite derived data from 1988 onwards showed shoreline regions experiencing the highest rates of seaward extension and landward retreat. The high temporal resolution of this data supports monitoring changes, such as the influence of the El Niño Southern Oscillation on beach rotation. Photogrammetry data with multidecadal temporal coverage provides insights into historical changes. Airborne LiDAR offers three-dimensional data with high spatial resolution to develop accurate terrain models as LiDAR pulses can penetrate foredune vegetation. RPA LiDAR and aerial image data delivered the highest spatial resolution of the beach and foredune region and improves capacity to understand and describe sediment dynamics within a beach or compartment. Rapid deployment capability of RPAs allows for immediate evaluation of impacts from episodic events including storms and management interventions, thereby enhancing hazard mitigation efforts, and improving knowledge of coastal processes. The framework presented in this study emphasises the importance of integrating complimentary monitoring technologies and datasets to improve the temporal and spatial relevance of projections that inform coastal management.