Morphological variability in the linear dunefields of the Strzelecki and Tirari Deserts, Australia

Linear dunefields dominate the arid centre of the Australian continent. The morphological variability of linear dunes in the Strzelecki and Tirari Deserts of Australia was assessed using a dune classification scheme based on quantifiable variables of substrate, spacing and junction frequency. The use of high spatial resolution ASTER satellite imagery enabled detailed analysis, including spectral characterisation of substrate, at both local and regional scales. The classification of the linear dunes revealed close relationships between substrate type and dune spacing, reflecting local sediment availability. Increasing dunefield organisation downwind is reflected in reduced numbers of dune junctions, and may suggest the attainment of dynamic morphological and sedimentological equilibrium. Both downwind evolution and sediment nourishment from local sources play a role in linear dune formation. Maps illustrating the spatial distribution of planimetric variables provide a useful tool for investigating linear dune behaviour, although additional variables such as height and dunefield age add to the complexity of dune formation and must also be considered.