Mapping reef islands in 3D
10-17, 11:25– (Pacific/Auckland), Plenary

We record the extent and shape of the beach over time to monitor coastal changes,

Reef islands and coral cays like Heron Island on the Great Barrier Reef are highly dynamic and change in shoreline horizontal and vertical positions can occur rapidly over days or slowly over years to decades. Reef island environments are severely impacted by sea level change and human activities like dredging and shoreline hardening. These impacts are likely to be exacerbated in a future of higher sea levels and changing wave climates. Despite this there are very few studies that have examined shoreline and volumetric change of low-lying reef islands over time. Measuring the horizontal position and three-dimensional volume of low-lying reef islands at high spatial resolution (< 1 m) and precision over several seasons and years will provide a better understanding of the processes driving shoreline change and coastal erosion and accretion. In June 2023, we collected field data on Heron Island to characterise the intertidal zone and beach area using drones, laser scanners, and GNSS. The results from this study will help inform shoreline monitoring, management strategies and mitigation measures, facilitate greater accuracy in modelling future island states, and help ensure sustainability of the island. The overall aim is to protect the important ecosystem reef islands provide and to offer insights into tropical island change that will be relevant globally and throughout the entire Great Barrier Reef.