GIS dataset of shallow closed depressions on the Nullarbor Plain, Australia - vector format (updated)

This dataset contains an updated spatial layer of mapped closed shallow karst depressions on the Nullarbor Plain, southern Australia. The depressions were semi-automatically detected from a digital surface model (DSM; TanDEM-X and TanDEM-X EDEM) using the Index of Topographic Openness (ITO), a terrain metric that quantifies local surface concavity and convexity by evaluating the angular openness of the surrounding topography. Depression boundaries were subsequently refined using the method of the outermost closed contour, whereby the outermost contour line in each depression was delineated to approximate the areal extent of individual depressions. In addition, areas dominated by non-carbonate rocks were excluded, and the resulting dataset includes an improved representation of shallow karst depressions. Given the large extent of the research area, the detected features were then subjected to manual inspection and correction inside 11 representative study areas. This validation step was carried out using high-resolution satellite imagery, digital terrain visualisations (e.g., DSM derivatives), and radiometric geophysical maps. Morphometric attributes were calculated for each depression, including area, perimeter, circularity, length, width, depth, and orientation. The dataset was produced as part of a master's study investigating the spatial distribution, morphology, sedimentary fill, and hydrological functioning of dayas under arid conditions. Coordinate reference system: GDA2020 GA Lambert Conformal Conic (GDA2020 GA LCC) Each polygon represents one depression. Attribute fields are described in the accompanying README file.