Australian National Multiscale Topography Models

The Topographic Position Index measures the topographic slope position of landforms by comparing the mean elevation of a specific neighbourhood area with the elevation value of a central cell. This is done for every cell or pixel in the digital elevation model (DEM) to derive the relative topographic position (e.g. upper, middle and lower landscape elements). Ruggedness informs on the roughness of the surface and is calculated as the standard deviation of elevations. Both these terrain components are used to generate a multi-scale topographic index over the Australian continent using the algorithm developed by Lindsay, J, B., Cockburn, J. M. H. and Russell, H. A. J., 2015. An integral image approach to performing multi-scale topographic position analysis, Geomorphology, 245, 51-61. Topographic position is captured across three spatial scale and display as a ternary image. The ternary image reveals a rich representation of nested landform features with broad application to geomorphological and hydrological process understanding and mapping of regolith and soils. Value: Broad application in understanding geomorphological and hydrological processes and in mapping regolith and soils over the Australian continent. Can be used as inputs into geospatial modelling and machine learning Scope: The dataset is national. The algorithm can be run on any digital elevation gridded dataset.