THE TRUTH IS IN HERE - APPLICATIONS OF HIGH RESOLUTION LIDAR, GROUND PENETRATING RADAR AND GIS FOR GEOMORPHIC MAPPING OF THE COOLOOLA SAND MASS DUNE UNITS

Southeast Queensland, Australia hosts large Pleistocene-aged sand islands and coastal dunefields that represent the terminus of the world’s largest downdrift littoral sediment system. Known as the Great Sandy Region, the area is home to the three largest sand islands in the world, namely Fraser Island, North Stradbroke Island and Moreton Island, as well as a large coastal dunefield welded to the mainland, the Cooloola Sand Mass. Within the Cooloola Sand Mass and nearby sand islands, successive phases of dune activity and stabilisation have resulted in a complex onlapping sequence of large parabolic dunes that reach heights up to 280 m above sea level. Early work conducted on the Cooloola Sand Mass focused on the soil development, vegetation and surface morphology of the dunefield, and was used as a basis for later work that mapped and correlated the different dune units preserved within the Great Sandy Region (Ward, 2006).

Building on previous work, we seek to refine the existing geomorphic mapping using high-resolution LiDAR-derived topography, soil sampling and ground penetrating radar integrated into a GIS framework. Results from field mapping and spatial analysis on Cooloola are presented here. Dune units have been defined by the sharpness of the dune crests, intensity of podzolisation and their level of erosion. At least eight units have been recognized. This supports the original mapping of Ward (2006) but highlights additional complexity in the Holocene part of the sequence. The results have provided insight into refining the models of evolution and relationships of soil and geomorphology. The latest results will be presented.